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* sdcardfs: remove unneeded __init and __exitDaniel Rosenberg2017-04-111-2/+2
| | | | Change-Id: I2a2d45d52f891332174c3000e8681c5167c1564f
* sdcardfs: Remove unused codeDaniel Rosenberg2017-04-111-2/+0
| | | | Change-Id: Ie97cba27ce44818ac56cfe40954f164ad44eccf6
* sdcardfs: remove effectless config optionDaniel Rosenberg2017-04-114-32/+1
| | | | | | | | | | CONFIG_SDCARD_FS_CI_SEARCH only guards a define for LOOKUP_CASE_INSENSITIVE, which is never used in the kernel. Remove both, along with the option matching that supports it. Change-Id: I363a8f31de8ee7a7a934d75300cc9ba8176e2edf Signed-off-by: Daniel Rosenberg <drosen@google.com>
* sdcardfs: Add support for d_canonicalizeDaniel Rosenberg2017-04-111-0/+1
| | | | | Change-Id: I5d6f0e71b8ca99aec4b0894412f1dfd1cfe12add Signed-off-by: Daniel Rosenberg <drosen@google.com>
* sdcardfs: Bring up to date with Android M permissions:Daniel Rosenberg2017-04-1110-611/+504
| | | | | | | In M, the workings of sdcardfs were changed significantly. This brings sdcardfs into line with the changes. Change-Id: I10e91a84a884c838feef7aa26c0a2b21f02e052e
* sdcardfs: Changed type-cast in packagelist managementDaniel Campello2017-04-111-19/+21
| | | | Change-Id: Ic8842de2d7274b7a5438938d2febf5d8da867148
* sdcardfs: port to 3.10Daniel Campello2017-04-1110-375/+129
| | | | Change-Id: I832a14cee3fcbf47ee6e5da2943a90f9dea5b60a
* Initial port of sdcardfsDaniel Campello2017-04-1117-2/+4119
| | | | Change-Id: I5b5772a2bbff9f3a7dda641644630a7b8afacec0
* Fix "Elevation of privilege vulnerability in kernel file system"fire8552017-04-111-5/+5
| | | | | | CVE-2017-0427 An elevation of privilege vulnerability in the kernel file system could enable a local malicious application to execute arbitrary code within the context of the kernel. This issue is rated as Critical due to the possibility of a local permanent device compromise, which may require reflashing the operating system to repair the device.
* ecryptfs: forbid opening files without mmap handlerJann Horn2017-04-111-2/+11
| | | | | | | | | | | This prevents users from triggering a stack overflow through a recursive invocation of pagefault handling that involves mapping procfs files into virtual memory. Signed-off-by: Jann Horn <jannh@google.com> Acked-by: Tyler Hicks <tyhicks@canonical.com> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* BACKPORT: smarter propagate_mnt()Al Viro2017-04-113-77/+127
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current mainline has copies propagated to *all* nodes, then tears down the copies we made for nodes that do not contain counterparts of the desired mountpoint. That sets the right propagation graph for the copies (at teardown time we move the slaves of removed node to a surviving peer or directly to master), but we end up paying a fairly steep price in useless allocations. It's fairly easy to create a situation where N calls of mount(2) create exactly N bindings, with O(N^2) vfsmounts allocated and freed in process. Fortunately, it is possible to avoid those allocations/freeings. The trick is to create copies in the right order and find which one would've eventually become a master with the current algorithm. It turns out to be possible in O(nodes getting propagation) time and with no extra allocations at all. One part is that we need to make sure that eventual master will be created before its slaves, so we need to walk the propagation tree in a different order - by peer groups. And iterate through the peers before dealing with the next group. Another thing is finding the (earlier) copy that will be a master of one we are about to create; to do that we are (temporary) marking the masters of mountpoints we are attaching the copies to. Either we are in a peer of the last mountpoint we'd dealt with, or we have the following situation: we are attaching to mountpoint M, the last copy S_0 had been attached to M_0 and there are sequences S_0...S_n, M_0...M_n such that S_{i+1} is a master of S_{i}, S_{i} mounted on M{i} and we need to create a slave of the first S_{k} such that M is getting propagation from M_{k}. It means that the master of M_{k} will be among the sequence of masters of M. On the other hand, the nearest marked node in that sequence will either be the master of M_{k} or the master of M_{k-1} (the latter - in the case if M_{k-1} is a slave of something M gets propagation from, but in a wrong peer group). So we go through the sequence of masters of M until we find a marked one (P). Let N be the one before it. Then we go through the sequence of masters of S_0 until we find one (say, S) mounted on a node D that has P as master and check if D is a peer of N. If it is, S will be the master of new copy, if not - the master of S will be. That's it for the hard part; the rest is fairly simple. Iterator is in next_group(), handling of one prospective mountpoint is propagate_one(). It seems to survive all tests and gives a noticably better performance than the current mainline for setups that are seriously using shared subtrees. Change-Id: I45648e8a405544f768c5956711bdbdf509e2705a Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* BACKPORT: don't bother with propagate_mnt() unless the target is sharedAl Viro2017-04-111-10/+7
| | | | | | | | | | If the dest_mnt is not shared, propagate_mnt() does nothing - there's no mounts to propagate to and thus no copies to create. Might as well don't bother calling it in that case. Change-Id: Id94af8ad288bf9bfc6ffb5570562bbc2dc2e0d87 Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* BACKPORT: aio: mark AIO pseudo-fs noexecNick Desaulniers2017-04-111-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This ensures that do_mmap() won't implicitly make AIO memory mappings executable if the READ_IMPLIES_EXEC personality flag is set. Such behavior is problematic because the security_mmap_file LSM hook doesn't catch this case, potentially permitting an attacker to bypass a W^X policy enforced by SELinux. I have tested the patch on my machine. To test the behavior, compile and run this: #define _GNU_SOURCE #include <unistd.h> #include <sys/personality.h> #include <linux/aio_abi.h> #include <err.h> #include <stdlib.h> #include <stdio.h> #include <sys/syscall.h> int main(void) { personality(READ_IMPLIES_EXEC); aio_context_t ctx = 0; if (syscall(__NR_io_setup, 1, &ctx)) err(1, "io_setup"); char cmd[1000]; sprintf(cmd, "cat /proc/%d/maps | grep -F '/[aio]'", (int)getpid()); system(cmd); return 0; } In the output, "rw-s" is good, "rwxs" is bad. Signed-off-by: Jann Horn <jann@thejh.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> (cherry picked from commit 22f6b4d34fcf039c63a94e7670e0da24f8575a5a) Bug: 31711619 Change-Id: I9f2872703bef240d6b82320c744529459bb076dc
* pstore/ram: Use memcpy_fromio() to save old bufferAndrew Bresticker2017-04-111-2/+2
| | | | | | | | | | | | | | | | | | commit d771fdf94180de2bd811ac90cba75f0f346abf8d upstream. The ramoops buffer may be mapped as either I/O memory or uncached memory. On ARM64, this results in a device-type (strongly-ordered) mapping. Since unnaligned accesses to device-type memory will generate an alignment fault (regardless of whether or not strict alignment checking is enabled), it is not safe to use memcpy(). memcpy_fromio() is guaranteed to only use aligned accesses, so use that instead. Signed-off-by: Andrew Bresticker <abrestic@chromium.org> Signed-off-by: Enric Balletbo Serra <enric.balletbo@collabora.com> Reviewed-by: Puneet Kumar <puneetster@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
* pstore/ram: Use memcpy_toio instead of memcpyFurquan Shaikh2017-04-111-1/+1
| | | | | | | | | | | | | | | | | | commit 7e75678d23167c2527e655658a8ef36a36c8b4d9 upstream. persistent_ram_update uses vmap / iomap based on whether the buffer is in memory region or reserved region. However, both map it as non-cacheable memory. For armv8 specifically, non-cacheable mapping requests use a memory type that has to be accessed aligned to the request size. memcpy() doesn't guarantee that. Signed-off-by: Furquan Shaikh <furquan@google.com> Signed-off-by: Enric Balletbo Serra <enric.balletbo@collabora.com> Reviewed-by: Aaron Durbin <adurbin@chromium.org> Reviewed-by: Olof Johansson <olofj@chromium.org> Tested-by: Furquan Shaikh <furquan@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
* pstore/core: drop cmpxchg based updatesSebastian Andrzej Siewior2017-04-111-41/+2
| | | | | | | | | | | | | | | | | | | | | | | commit d5a9bf0b38d2ac85c9a693c7fb851f74fd2a2494 upstream. I have here a FPGA behind PCIe which exports SRAM which I use for pstore. Now it seems that the FPGA no longer supports cmpxchg based updates and writes back 0xff…ff and returns the same. This leads to crash during crash rendering pstore useless. Since I doubt that there is much benefit from using cmpxchg() here, I am dropping this atomic access and use the spinlock based version. Cc: Anton Vorontsov <anton@enomsg.org> Cc: Colin Cross <ccross@android.com> Cc: Kees Cook <keescook@chromium.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Rabin Vincent <rabinv@axis.com> Tested-by: Rabin Vincent <rabinv@axis.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Guenter Roeck <linux@roeck-us.net> [kees: remove "_locked" suffix since it's the only option now] Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
* pstore: Fix buffer overflow while write offset equal to buffer sizeLiu ShuoX2017-04-111-2/+2
| | | | | | | | | | | | commit 017321cf390045dd4c4afc4a232995ea50bcf66d upstream. In case new offset is equal to prz->buffer_size, it won't wrap at this time and will return old(overflow) value next time. Signed-off-by: Liu ShuoX <shuox.liu@intel.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
* hostfs: Freeing an ERR_PTR in hostfs_fill_sb_common()Dan Carpenter2017-04-111-3/+4
| | | | | | | | | | | commit 8a545f185145e3c09348cd74326268ecfc6715a3 upstream. We can't pass error pointers to kfree() or it causes an oops. Fixes: 52b209f7b848 ('get rid of hostfs_read_inode()') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Willy Tarreau <w@1wt.eu>
* isofs: Do not return EACCES for unknown filesystemsJan Kara2017-04-111-3/+5
| | | | | | | | | | | | | | | | | | commit a2ed0b391dd9c3ef1d64c7c3e370f4a5ffcd324a upstream. When isofs_mount() is called to mount a device read-write, it returns EACCES even before it checks that the device actually contains an isofs filesystem. This may confuse mount(8) which then tries to mount all subsequent filesystem types in read-only mode. Fix the problem by returning EACCES only once we verify that the device indeed contains an iso9660 filesystem. Fixes: 17b7f7cf58926844e1dd40f5eb5348d481deca6a Reported-by: Kent Overstreet <kent.overstreet@gmail.com> Reported-by: Karel Zak <kzak@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Willy Tarreau <w@1wt.eu>
* fs/super.c: fix race between freeze_super() and thaw_super()Oleg Nesterov2017-04-111-3/+3
| | | | | | | | | | | | | | | | | | commit 89f39af129382a40d7cd1f6914617282cfeee28e upstream. Change thaw_super() to check frozen != SB_FREEZE_COMPLETE rather than frozen == SB_UNFROZEN, otherwise it can race with freeze_super() which drops sb->s_umount after SB_FREEZE_WRITE to preserve the lock ordering. In this case thaw_super() will wrongly call s_op->unfreeze_fs() before it was actually frozen, and call sb_freeze_unlock() which leads to the unbalanced percpu_up_write(). Unfortunately lockdep can't detect this, so this triggers misc BUG_ON()'s in kernel/rcu/sync.c. Reported-and-tested-by: Nikolay Borisov <kernel@kyup.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
* NFSv4: Open state recovery must account for file permission changesTrond Myklebust2017-04-111-0/+3
| | | | | | | | | | | | | commit 304020fe48c6c7fff8b5a38f382b54404f0f79d3 upstream. If the file permissions change on the server, then we may not be able to recover open state. If so, we need to ensure that we mark the file descriptor appropriately. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Tested-by: Oleg Drokin <green@linuxhacker.ru> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
* NFS: Don't drop CB requests with invalid principalsChuck Lever2017-04-111-1/+5
| | | | | | | | | | | | | | | | | commit a4e187d83d88eeaba6252aac0a2ffe5eaa73a818 upstream. Before commit 778be232a207 ("NFS do not find client in NFSv4 pg_authenticate"), the Linux callback server replied with RPC_AUTH_ERROR / RPC_AUTH_BADCRED, instead of dropping the CB request. Let's restore that behavior so the server has a chance to do something useful about it, and provide a warning that helps admins correct the problem. Fixes: 778be232a207 ("NFS do not find client in NFSv4 ...") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
* NFSD: Using free_conn free connectionKinglong Mee2017-04-111-1/+2
| | | | | | | | | | | commit 3f42d2c428c724212c5f4249daea97e254eb0546 upstream. Connection from alloc_conn must be freed through free_conn, otherwise, the reference of svc_xprt will never be put. Signed-off-by: Kinglong Mee <kinglongmee@gmail.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
* NFSv4.x: Fix a refcount leak in nfs_callback_up_netTrond Myklebust2017-04-111-0/+1
| | | | | | | | | | commit 98b0f80c2396224bbbed81792b526e6c72ba9efa upstream. On error, the callers expect us to return without bumping nn->cb_users[]. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
* ubifs: Fix regression in ubifs_readdir()Richard Weinberger2017-04-111-0/+8
| | | | | | | | | | | | | | | | commit a00052a296e54205cf238c75bd98d17d5d02a6db upstream. Commit c83ed4c9dbb35 ("ubifs: Abort readdir upon error") broke overlayfs support because the fix exposed an internal error code to VFS. Reported-by: Peter Rosin <peda@axentia.se> Tested-by: Peter Rosin <peda@axentia.se> Reported-by: Ralph Sennhauser <ralph.sennhauser@gmail.com> Tested-by: Ralph Sennhauser <ralph.sennhauser@gmail.com> Fixes: c83ed4c9dbb35 ("ubifs: Abort readdir upon error") Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Willy Tarreau <w@1wt.eu>
* ubifs: Abort readdir upon errorRichard Weinberger2017-04-111-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | commit c83ed4c9dbb358b9e7707486e167e940d48bfeed upstream. If UBIFS is facing an error while walking a directory, it reports this error and ubifs_readdir() returns the error code. But the VFS readdir logic does not make the getdents system call fail in all cases. When the readdir cursor indicates that more entries are present, the system call will just return and the libc wrapper will try again since it also knows that more entries are present. This causes the libc wrapper to busy loop for ever when a directory is corrupted on UBIFS. A common approach do deal with corrupted directory entries is skipping them by setting the cursor to the next entry. On UBIFS this approach is not possible since we cannot compute the next directory entry cursor position without reading the current entry. So all we can do is setting the cursor to the "no more entries" position and make getdents exit. Signed-off-by: Richard Weinberger <richard@nod.at> [wt: adjusted context] Signed-off-by: Willy Tarreau <w@1wt.eu>
* UBIFS: Fix possible memory leak in ubifs_readdir()Richard Weinberger2017-04-111-2/+3
| | | | | | | | | | | commit aeeb14f763917ccf639a602cfbeee6957fd944a2 upstream. If ubifs_tnc_next_ent() returns something else than -ENOENT we leak file->private_data. Signed-off-by: Richard Weinberger <richard@nod.at> Reviewed-by: David Gstir <david@sigma-star.at> Signed-off-by: Willy Tarreau <w@1wt.eu>
* ubifs: Fix xattr_names length in exit pathsRichard Weinberger2017-04-111-0/+2
| | | | | | | | | | | commit 843741c5778398ea67055067f4cc65ae6c80ca0e upstream. When the operation fails we also have to undo the changes we made to ->xattr_names. Otherwise listxattr() will report wrong lengths. Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Willy Tarreau <w@1wt.eu>
* ubifs: Fix assertion in layout_in_gaps()Vincent Stehlé2017-04-111-1/+1
| | | | | | | | | | | | | | | | | commit c0082e985fdf77b02fc9e0dac3b58504dcf11b7a upstream. An assertion in layout_in_gaps() verifies that the gap_lebs pointer is below the maximum bound. When computing this maximum bound the idx_lebs count is multiplied by sizeof(int), while C pointers arithmetic does take into account the size of the pointed elements implicitly already. Remove the multiplication to fix the assertion. Fixes: 1e51764a3c2ac05a ("UBIFS: add new flash file system") Signed-off-by: Vincent Stehlé <vincent.stehle@intel.com> Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Willy Tarreau <w@1wt.eu>
* ocfs2: fix start offset to ocfs2_zero_range_for_truncate()Ashish Samant2017-04-111-10/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit d21c353d5e99c56cdd5b5c1183ffbcaf23b8b960 upstream. If we punch a hole on a reflink such that following conditions are met: 1. start offset is on a cluster boundary 2. end offset is not on a cluster boundary 3. (end offset is somewhere in another extent) or (hole range > MAX_CONTIG_BYTES(1MB)), we dont COW the first cluster starting at the start offset. But in this case, we were wrongly passing this cluster to ocfs2_zero_range_for_truncate() to zero out. This will modify the cluster in place and zero it in the source too. Fix this by skipping this cluster in such a scenario. To reproduce: 1. Create a random file of say 10 MB xfs_io -c 'pwrite -b 4k 0 10M' -f 10MBfile 2. Reflink it reflink -f 10MBfile reflnktest 3. Punch a hole at starting at cluster boundary with range greater that 1MB. You can also use a range that will put the end offset in another extent. fallocate -p -o 0 -l 1048615 reflnktest 4. sync 5. Check the first cluster in the source file. (It will be zeroed out). dd if=10MBfile iflag=direct bs=<cluster size> count=1 | hexdump -C Link: http://lkml.kernel.org/r/1470957147-14185-1-git-send-email-ashish.samant@oracle.com Signed-off-by: Ashish Samant <ashish.samant@oracle.com> Reported-by: Saar Maoz <saar.maoz@oracle.com> Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com> Cc: Mark Fasheh <mfasheh@versity.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <joseph.qi@huawei.com> Cc: Eric Ren <zren@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
* ocfs2/dlm: fix race between convert and migrationJoseph Qi2017-04-111-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit e6f0c6e6170fec175fe676495f29029aecdf486c upstream. Commit ac7cf246dfdb ("ocfs2/dlm: fix race between convert and recovery") checks if lockres master has changed to identify whether new master has finished recovery or not. This will introduce a race that right after old master does umount ( means master will change), a new convert request comes. In this case, it will reset lockres state to DLM_RECOVERING and then retry convert, and then fail with lockres->l_action being set to OCFS2_AST_INVALID, which will cause inconsistent lock level between ocfs2 and dlm, and then finally BUG. Since dlm recovery will clear lock->convert_pending in dlm_move_lockres_to_recovery_list, we can use it to correctly identify the race case between convert and recovery. So fix it. Fixes: ac7cf246dfdb ("ocfs2/dlm: fix race between convert and recovery") Link: http://lkml.kernel.org/r/57CE1569.8010704@huawei.com Signed-off-by: Joseph Qi <joseph.qi@huawei.com> Signed-off-by: Jun Piao <piaojun@huawei.com> Cc: Mark Fasheh <mfasheh@versity.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
* btrfs: ensure that file descriptor used with subvol ioctls is a dirJeff Mahoney2017-04-111-0/+12
| | | | | | | | | | | | | | | | commit 325c50e3cebb9208009083e841550f98a863bfa0 upstream. If the subvol/snapshot create/destroy ioctls are passed a regular file with execute permissions set, we'll eventually Oops while trying to do inode->i_op->lookup via lookup_one_len. This patch ensures that the file descriptor refers to a directory. Fixes: cb8e70901d (Btrfs: Fix subvolume creation locking rules) Fixes: 76dda93c6a (Btrfs: add snapshot/subvolume destroy ioctl) Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
* libxfs: clean up _calc_dquots_per_chunkDarrick J. Wong2017-04-111-2/+1
| | | | | | | | | | | | | | commit 58d789678546d46d7bbd809dd7dab417c0f23655 upstream. The function xfs_calc_dquots_per_chunk takes a parameter in units of basic blocks. The kernel seems to get the units wrong, but userspace got 'fixed' by commenting out the unnecessary conversion. Fix both. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
* xfs: fix superblock inprogress checkDave Chinner2017-04-111-1/+2
| | | | | | | | | | | | | | | | | | | | | | | commit f3d7ebdeb2c297bd26272384e955033493ca291c upstream. From inspection, the superblock sb_inprogress check is done in the verifier and triggered only for the primary superblock via a "bp->b_bn == XFS_SB_DADDR" check. Unfortunately, the primary superblock is an uncached buffer, and hence it is configured by xfs_buf_read_uncached() with: bp->b_bn = XFS_BUF_DADDR_NULL; /* always null for uncached buffers */ And so this check never triggers. Fix it. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com> [wt: s/xfs_sb.c/xfs_mount.c in 3.10] Signed-off-by: Willy Tarreau <w@1wt.eu>
* reiserfs: Unlock superblock before calling reiserfs_quota_on_mount()Mike Galbraith2017-04-111-1/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 420902c9d086848a7548c83e0a49021514bd71b7 upstream. If we hold the superblock lock while calling reiserfs_quota_on_mount(), we can deadlock our own worker - mount blocks kworker/3:2, sleeps forever more. crash> ps|grep UN 715 2 3 ffff880220734d30 UN 0.0 0 0 [kworker/3:2] 9369 9341 2 ffff88021ffb7560 UN 1.3 493404 123184 Xorg 9665 9664 3 ffff880225b92ab0 UN 0.0 47368 812 udisks-daemon 10635 10403 3 ffff880222f22c70 UN 0.0 14904 936 mount crash> bt ffff880220734d30 PID: 715 TASK: ffff880220734d30 CPU: 3 COMMAND: "kworker/3:2" #0 [ffff8802244c3c20] schedule at ffffffff8144584b #1 [ffff8802244c3cc8] __rt_mutex_slowlock at ffffffff814472b3 #2 [ffff8802244c3d28] rt_mutex_slowlock at ffffffff814473f5 #3 [ffff8802244c3dc8] reiserfs_write_lock at ffffffffa05f28fd [reiserfs] #4 [ffff8802244c3de8] flush_async_commits at ffffffffa05ec91d [reiserfs] #5 [ffff8802244c3e08] process_one_work at ffffffff81073726 #6 [ffff8802244c3e68] worker_thread at ffffffff81073eba #7 [ffff8802244c3ec8] kthread at ffffffff810782e0 #8 [ffff8802244c3f48] kernel_thread_helper at ffffffff81450064 crash> rd ffff8802244c3cc8 10 ffff8802244c3cc8: ffffffff814472b3 ffff880222f23250 .rD.....P2.".... ffff8802244c3cd8: 0000000000000000 0000000000000286 ................ ffff8802244c3ce8: ffff8802244c3d30 ffff880220734d80 0=L$.....Ms .... ffff8802244c3cf8: ffff880222e8f628 0000000000000000 (.."............ ffff8802244c3d08: 0000000000000000 0000000000000002 ................ crash> struct rt_mutex ffff880222e8f628 struct rt_mutex { wait_lock = { raw_lock = { slock = 65537 } }, wait_list = { node_list = { next = 0xffff8802244c3d48, prev = 0xffff8802244c3d48 } }, owner = 0xffff880222f22c71, save_state = 0 } crash> bt 0xffff880222f22c70 PID: 10635 TASK: ffff880222f22c70 CPU: 3 COMMAND: "mount" #0 [ffff8802216a9868] schedule at ffffffff8144584b #1 [ffff8802216a9910] schedule_timeout at ffffffff81446865 #2 [ffff8802216a99a0] wait_for_common at ffffffff81445f74 #3 [ffff8802216a9a30] flush_work at ffffffff810712d3 #4 [ffff8802216a9ab0] schedule_on_each_cpu at ffffffff81074463 #5 [ffff8802216a9ae0] invalidate_bdev at ffffffff81178aba #6 [ffff8802216a9af0] vfs_load_quota_inode at ffffffff811a3632 #7 [ffff8802216a9b50] dquot_quota_on_mount at ffffffff811a375c #8 [ffff8802216a9b80] finish_unfinished at ffffffffa05dd8b0 [reiserfs] #9 [ffff8802216a9cc0] reiserfs_fill_super at ffffffffa05de825 [reiserfs] RIP: 00007f7b9303997a RSP: 00007ffff443c7a8 RFLAGS: 00010202 RAX: 00000000000000a5 RBX: ffffffff8144ef12 RCX: 00007f7b932e9ee0 RDX: 00007f7b93d9a400 RSI: 00007f7b93d9a3e0 RDI: 00007f7b93d9a3c0 RBP: 00007f7b93d9a2c0 R8: 00007f7b93d9a550 R9: 0000000000000001 R10: ffffffffc0ed040e R11: 0000000000000202 R12: 000000000000040e R13: 0000000000000000 R14: 00000000c0ed040e R15: 00007ffff443ca20 ORIG_RAX: 00000000000000a5 CS: 0033 SS: 002b Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Mike Galbraith <mgalbraith@suse.de> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Willy Tarreau <w@1wt.eu>
* reiserfs: fix "new_insert_key may be used uninitialized ..."Jeff Mahoney2017-04-111-1/+2
| | | | | | | | | | | | | | | | | | commit 0a11b9aae49adf1f952427ef1a1d9e793dd6ffb6 upstream. new_insert_key only makes any sense when it's associated with a new_insert_ptr, which is initialized to NULL and changed to a buffer_head when we also initialize new_insert_key. We can key off of that to avoid the uninitialized warning. Link: http://lkml.kernel.org/r/5eca5ffb-2155-8df2-b4a2-f162f105efed@suse.com Signed-off-by: Jeff Mahoney <jeffm@suse.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Jan Kara <jack@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
* ext4: sanity check the block and cluster size at mount timeTheodore Ts'o2017-04-112-1/+17
| | | | | | | | | | | | | | | commit 8cdf3372fe8368f56315e66bea9f35053c418093 upstream. If the block size or cluster size is insane, reject the mount. This is important for security reasons (although we shouldn't be just depending on this check). Ref: http://www.securityfocus.com/archive/1/539661 Ref: https://bugzilla.redhat.com/show_bug.cgi?id=1332506 Reported-by: Borislav Petkov <bp@alien8.de> Reported-by: Nikolay Borisov <kernel@kyup.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Willy Tarreau <w@1wt.eu>
* ext4: allow DAX writeback for hole punchRoss Zwisler2017-04-111-2/+2
| | | | | | | | | | | | | | commit cca32b7eeb4ea24fa6596650e06279ad9130af98 upstream. Currently when doing a DAX hole punch with ext4 we fail to do a writeback. This is because the logic around filemap_write_and_wait_range() in ext4_punch_hole() only looks for dirty page cache pages in the radix tree, not for dirty DAX exceptional entries. Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Willy Tarreau <w@1wt.eu>
* ext4: reinforce check of i_dtime when clearing high fields of uid and gidDaeho Jeong2017-04-111-4/+4
| | | | | | | | | | | | | | | | | | | | | | | commit 93e3b4e6631d2a74a8cf7429138096862ff9f452 upstream. Now, ext4_do_update_inode() clears high 16-bit fields of uid/gid of deleted and evicted inode to fix up interoperability with old kernels. However, it checks only i_dtime of an inode to determine whether the inode was deleted and evicted, and this is very risky, because i_dtime can be used for the pointer maintaining orphan inode list, too. We need to further check whether the i_dtime is being used for the orphan inode list even if the i_dtime is not NULL. We found that high 16-bit fields of uid/gid of inode are unintentionally and permanently cleared when the inode truncation is just triggered, but not finished, and the inode metadata, whose high uid/gid bits are cleared, is written on disk, and the sudden power-off follows that in order. Signed-off-by: Daeho Jeong <daeho.jeong@samsung.com> Signed-off-by: Hobin Woo <hobin.woo@samsung.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Willy Tarreau <w@1wt.eu>
* ext4: use __GFP_NOFAIL in ext4_free_blocks()Konstantin Khlebnikov2017-04-111-19/+28
| | | | | | | | | | | | | commit adb7ef600cc9d9d15ecc934cc26af5c1379777df upstream. This might be unexpected but pages allocated for sbi->s_buddy_cache are charged to current memory cgroup. So, GFP_NOFS allocation could fail if current task has been killed by OOM or if current memory cgroup has no free memory left. Block allocator cannot handle such failures here yet. Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Willy Tarreau <w@1wt.eu>
* ext4: avoid modifying checksum fields directly during checksum verificationDaeho Jeong2017-04-114-36/+42
| | | | | | | | | | | | | | | | | | commit b47820edd1634dc1208f9212b7ecfb4230610a23 upstream. We temporally change checksum fields in buffers of some types of metadata into '0' for verifying the checksum values. By doing this without locking the buffer, some metadata's checksums, which are being committed or written back to the storage, could be damaged. In our test, several metadata blocks were found with damaged metadata checksum value during recovery process. When we only verify the checksum value, we have to avoid modifying checksum fields directly. Signed-off-by: Daeho Jeong <daeho.jeong@samsung.com> Signed-off-by: Youngjin Gil <youngjin.gil@samsung.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
* ext4: validate that metadata blocks do not overlap superblockTheodore Ts'o2017-04-111-1/+17
| | | | | | | | | | | | | | commit 829fa70dddadf9dd041d62b82cd7cea63943899d upstream. A number of fuzzing failures seem to be caused by allocation bitmaps or other metadata blocks being pointed at the superblock. This can cause kernel BUG or WARNings once the superblock is overwritten, so validate the group descriptor blocks to make sure this doesn't happen. Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Willy Tarreau <w@1wt.eu>
* coredump: fix unfreezable coredumping taskAndrey Ryabinin2017-04-111-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 70d78fe7c8b640b5acfad56ad341985b3810998a upstream. It could be not possible to freeze coredumping task when it waits for 'core_state->startup' completion, because threads are frozen in get_signal() before they got a chance to complete 'core_state->startup'. Inability to freeze a task during suspend will cause suspend to fail. Also CRIU uses cgroup freezer during dump operation. So with an unfreezable task the CRIU dump will fail because it waits for a transition from 'FREEZING' to 'FROZEN' state which will never happen. Use freezer_do_not_count() to tell freezer to ignore coredumping task while it waits for core_state->startup completion. Link: http://lkml.kernel.org/r/1475225434-3753-1-git-send-email-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Pavel Machek <pavel@ucw.cz> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Tejun Heo <tj@kernel.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
* UPSTREAM: proc: prevent accessing /proc/<PID>/environ until it's readyMathias Krause2017-04-111-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | (cherry picked from commit 8148a73c9901a8794a50f950083c00ccf97d43b3) If /proc/<PID>/environ gets read before the envp[] array is fully set up in create_{aout,elf,elf_fdpic,flat}_tables(), we might end up trying to read more bytes than are actually written, as env_start will already be set but env_end will still be zero, making the range calculation underflow, allowing to read beyond the end of what has been written. Fix this as it is done for /proc/<PID>/cmdline by testing env_end for zero. It is, apparently, intentionally set last in create_*_tables(). This bug was found by the PaX size_overflow plugin that detected the arithmetic underflow of 'this_len = env_end - (env_start + src)' when env_end is still zero. The expected consequence is that userland trying to access /proc/<PID>/environ of a not yet fully set up process may get inconsistent data as we're in the middle of copying in the environment variables. Fixes: https://forums.grsecurity.net/viewtopic.php?f=3&t=4363 Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=116461 Signed-off-by: Mathias Krause <minipli@googlemail.com> Cc: Emese Revfy <re.emese@gmail.com> Cc: Pax Team <pageexec@freemail.hu> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Mateusz Guzik <mguzik@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Jarod Wilson <jarod@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Change-Id: Ia2f58d48c15478ed4b6e237b63e704c70ff21e96 Bug: 30951939
* fs/seq_file: fix out-of-bounds readVegard Nossum2017-04-111-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 088bf2ff5d12e2e32ee52a4024fec26e582f44d3 upstream. seq_read() is a nasty piece of work, not to mention buggy. It has (I think) an old bug which allows unprivileged userspace to read beyond the end of m->buf. I was getting these: BUG: KASAN: slab-out-of-bounds in seq_read+0xcd2/0x1480 at addr ffff880116889880 Read of size 2713 by task trinity-c2/1329 CPU: 2 PID: 1329 Comm: trinity-c2 Not tainted 4.8.0-rc1+ #96 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014 Call Trace: kasan_object_err+0x1c/0x80 kasan_report_error+0x2cb/0x7e0 kasan_report+0x4e/0x80 check_memory_region+0x13e/0x1a0 kasan_check_read+0x11/0x20 seq_read+0xcd2/0x1480 proc_reg_read+0x10b/0x260 do_loop_readv_writev.part.5+0x140/0x2c0 do_readv_writev+0x589/0x860 vfs_readv+0x7b/0xd0 do_readv+0xd8/0x2c0 SyS_readv+0xb/0x10 do_syscall_64+0x1b3/0x4b0 entry_SYSCALL64_slow_path+0x25/0x25 Object at ffff880116889100, in cache kmalloc-4096 size: 4096 Allocated: PID = 1329 save_stack_trace+0x26/0x80 save_stack+0x46/0xd0 kasan_kmalloc+0xad/0xe0 __kmalloc+0x1aa/0x4a0 seq_buf_alloc+0x35/0x40 seq_read+0x7d8/0x1480 proc_reg_read+0x10b/0x260 do_loop_readv_writev.part.5+0x140/0x2c0 do_readv_writev+0x589/0x860 vfs_readv+0x7b/0xd0 do_readv+0xd8/0x2c0 SyS_readv+0xb/0x10 do_syscall_64+0x1b3/0x4b0 return_from_SYSCALL_64+0x0/0x6a Freed: PID = 0 (stack is not available) Memory state around the buggy address: ffff88011688a000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88011688a080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88011688a100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88011688a180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88011688a200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Disabling lock debugging due to kernel taint This seems to be the same thing that Dave Jones was seeing here: https://lkml.org/lkml/2016/8/12/334 There are multiple issues here: 1) If we enter the function with a non-empty buffer, there is an attempt to flush it. But it was not clearing m->from after doing so, which means that if we try to do this flush twice in a row without any call to traverse() in between, we are going to be reading from the wrong place -- the splat above, fixed by this patch. 2) If there's a short write to userspace because of page faults, the buffer may already contain multiple lines (i.e. pos has advanced by more than 1), but we don't save the progress that was made so the next call will output what we've already returned previously. Since that is a much less serious issue (and I have a headache after staring at seq_read() for the past 8 hours), I'll leave that for now. Link: http://lkml.kernel.org/r/1471447270-32093-1-git-send-email-vegard.nossum@oracle.com Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Reported-by: Dave Jones <davej@codemonkey.org.uk> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
* Revert "proc: Remove verifiedbootstate flag from /proc/cmdline"mm-6.0Moyster2016-11-241-27/+1
| | | | | | This commit breaks Offline Charging mode on Mediatek platforms (at least mt6753 and mt6795) This reverts commit 81cd48af4ce91983fa556039f52bdede850c4e52.
* UPSTREAM: capabilities: ambient capabilitiesAndy Lutomirski2016-11-181-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Credit where credit is due: this idea comes from Christoph Lameter with a lot of valuable input from Serge Hallyn. This patch is heavily based on Christoph's patch. ===== The status quo ===== On Linux, there are a number of capabilities defined by the kernel. To perform various privileged tasks, processes can wield capabilities that they hold. Each task has four capability masks: effective (pE), permitted (pP), inheritable (pI), and a bounding set (X). When the kernel checks for a capability, it checks pE. The other capability masks serve to modify what capabilities can be in pE. Any task can remove capabilities from pE, pP, or pI at any time. If a task has a capability in pP, it can add that capability to pE and/or pI. If a task has CAP_SETPCAP, then it can add any capability to pI, and it can remove capabilities from X. Tasks are not the only things that can have capabilities; files can also have capabilities. A file can have no capabilty information at all [1]. If a file has capability information, then it has a permitted mask (fP) and an inheritable mask (fI) as well as a single effective bit (fE) [2]. File capabilities modify the capabilities of tasks that execve(2) them. A task that successfully calls execve has its capabilities modified for the file ultimately being excecuted (i.e. the binary itself if that binary is ELF or for the interpreter if the binary is a script.) [3] In the capability evolution rules, for each mask Z, pZ represents the old value and pZ' represents the new value. The rules are: pP' = (X & fP) | (pI & fI) pI' = pI pE' = (fE ? pP' : 0) X is unchanged For setuid binaries, fP, fI, and fE are modified by a moderately complicated set of rules that emulate POSIX behavior. Similarly, if euid == 0 or ruid == 0, then fP, fI, and fE are modified differently (primary, fP and fI usually end up being the full set). For nonroot users executing binaries with neither setuid nor file caps, fI and fP are empty and fE is false. As an extra complication, if you execute a process as nonroot and fE is set, then the "secure exec" rules are in effect: AT_SECURE gets set, LD_PRELOAD doesn't work, etc. This is rather messy. We've learned that making any changes is dangerous, though: if a new kernel version allows an unprivileged program to change its security state in a way that persists cross execution of a setuid program or a program with file caps, this persistent state is surprisingly likely to allow setuid or file-capped programs to be exploited for privilege escalation. ===== The problem ===== Capability inheritance is basically useless. If you aren't root and you execute an ordinary binary, fI is zero, so your capabilities have no effect whatsoever on pP'. This means that you can't usefully execute a helper process or a shell command with elevated capabilities if you aren't root. On current kernels, you can sort of work around this by setting fI to the full set for most or all non-setuid executable files. This causes pP' = pI for nonroot, and inheritance works. No one does this because it's a PITA and it isn't even supported on most filesystems. If you try this, you'll discover that every nonroot program ends up with secure exec rules, breaking many things. This is a problem that has bitten many people who have tried to use capabilities for anything useful. ===== The proposed change ===== This patch adds a fifth capability mask called the ambient mask (pA). pA does what most people expect pI to do. pA obeys the invariant that no bit can ever be set in pA if it is not set in both pP and pI. Dropping a bit from pP or pI drops that bit from pA. This ensures that existing programs that try to drop capabilities still do so, with a complication. Because capability inheritance is so broken, setting KEEPCAPS, using setresuid to switch to nonroot uids, and then calling execve effectively drops capabilities. Therefore, setresuid from root to nonroot conditionally clears pA unless SECBIT_NO_SETUID_FIXUP is set. Processes that don't like this can re-add bits to pA afterwards. The capability evolution rules are changed: pA' = (file caps or setuid or setgid ? 0 : pA) pP' = (X & fP) | (pI & fI) | pA' pI' = pI pE' = (fE ? pP' : pA') X is unchanged If you are nonroot but you have a capability, you can add it to pA. If you do so, your children get that capability in pA, pP, and pE. For example, you can set pA = CAP_NET_BIND_SERVICE, and your children can automatically bind low-numbered ports. Hallelujah! Unprivileged users can create user namespaces, map themselves to a nonzero uid, and create both privileged (relative to their namespace) and unprivileged process trees. This is currently more or less impossible. Hallelujah! You cannot use pA to try to subvert a setuid, setgid, or file-capped program: if you execute any such program, pA gets cleared and the resulting evolution rules are unchanged by this patch. Users with nonzero pA are unlikely to unintentionally leak that capability. If they run programs that try to drop privileges, dropping privileges will still work. It's worth noting that the degree of paranoia in this patch could possibly be reduced without causing serious problems. Specifically, if we allowed pA to persist across executing non-pA-aware setuid binaries and across setresuid, then, naively, the only capabilities that could leak as a result would be the capabilities in pA, and any attacker *already* has those capabilities. This would make me nervous, though -- setuid binaries that tried to privilege-separate might fail to do so, and putting CAP_DAC_READ_SEARCH or CAP_DAC_OVERRIDE into pA could have unexpected side effects. (Whether these unexpected side effects would be exploitable is an open question.) I've therefore taken the more paranoid route. We can revisit this later. An alternative would be to require PR_SET_NO_NEW_PRIVS before setting ambient capabilities. I think that this would be annoying and would make granting otherwise unprivileged users minor ambient capabilities (CAP_NET_BIND_SERVICE or CAP_NET_RAW for example) much less useful than it is with this patch. ===== Footnotes ===== [1] Files that are missing the "security.capability" xattr or that have unrecognized values for that xattr end up with has_cap set to false. The code that does that appears to be complicated for no good reason. [2] The libcap capability mask parsers and formatters are dangerously misleading and the documentation is flat-out wrong. fE is *not* a mask; it's a single bit. This has probably confused every single person who has tried to use file capabilities. [3] Linux very confusingly processes both the script and the interpreter if applicable, for reasons that elude me. The results from thinking about a script's file capabilities and/or setuid bits are mostly discarded. Preliminary userspace code is here, but it needs updating: https://git.kernel.org/cgit/linux/kernel/git/luto/util-linux-playground.git/commit/?h=cap_ambient&id=7f5afbd175d2 Here is a test program that can be used to verify the functionality (from Christoph): /* * Test program for the ambient capabilities. This program spawns a shell * that allows running processes with a defined set of capabilities. * * (C) 2015 Christoph Lameter <cl@linux.com> * Released under: GPL v3 or later. * * * Compile using: * * gcc -o ambient_test ambient_test.o -lcap-ng * * This program must have the following capabilities to run properly: * Permissions for CAP_NET_RAW, CAP_NET_ADMIN, CAP_SYS_NICE * * A command to equip the binary with the right caps is: * * setcap cap_net_raw,cap_net_admin,cap_sys_nice+p ambient_test * * * To get a shell with additional caps that can be inherited by other processes: * * ./ambient_test /bin/bash * * * Verifying that it works: * * From the bash spawed by ambient_test run * * cat /proc/$$/status * * and have a look at the capabilities. */ /* * Definitions from the kernel header files. These are going to be removed * when the /usr/include files have these defined. */ static void set_ambient_cap(int cap) { int rc; capng_get_caps_process(); rc = capng_update(CAPNG_ADD, CAPNG_INHERITABLE, cap); if (rc) { printf("Cannot add inheritable cap\n"); exit(2); } capng_apply(CAPNG_SELECT_CAPS); /* Note the two 0s at the end. Kernel checks for these */ if (prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_RAISE, cap, 0, 0)) { perror("Cannot set cap"); exit(1); } } int main(int argc, char **argv) { int rc; set_ambient_cap(CAP_NET_RAW); set_ambient_cap(CAP_NET_ADMIN); set_ambient_cap(CAP_SYS_NICE); printf("Ambient_test forking shell\n"); if (execv(argv[1], argv + 1)) perror("Cannot exec"); return 0; } Signed-off-by: Christoph Lameter <cl@linux.com> # Original author Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Aaron Jones <aaronmdjones@gmail.com> Cc: Ted Ts'o <tytso@mit.edu> Cc: Andrew G. Morgan <morgan@kernel.org> Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: Austin S Hemmelgarn <ahferroin7@gmail.com> Cc: Markku Savela <msa@moth.iki.fi> Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: James Morris <james.l.morris@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> (cherry picked from commit 58319057b7847667f0c9585b9de0e8932b0fdb08) Bug: 31038224 Change-Id: I88bc5caa782dc6be23dc7e839ff8e11b9a903f8c Signed-off-by: Jorge Lucangeli Obes <jorgelo@google.com>
* ext4: fix potential use after free in __ext4_journal_stopLukas Czerner2016-11-171-1/+7
| | | | | | | | | | | | | | | | There is a use-after-free possibility in __ext4_journal_stop() in the case that we free the handle in the first jbd2_journal_stop() because we're referencing handle->h_err afterwards. This was introduced in 9705acd63b125dee8b15c705216d7186daea4625 and it is wrong. Fix it by storing the handle->h_err value beforehand and avoid referencing potentially freed handle. Issue: CYNGNOS-3304 Change-Id: I6e969a7f6214479d6b60627307327e5b720e338c Fixes: 9705acd63b125dee8b15c705216d7186daea4625 Signed-off-by: Lukas Czerner <lczerner@redhat.com> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Cc: stable@vger.kernel.org
* block: fix use-after-free in sys_ioprio_get()Omar Sandoval2016-11-171-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | get_task_ioprio() accesses the task->io_context without holding the task lock and thus can race with exit_io_context(), leading to a use-after-free. The reproducer below hits this within a few seconds on my 4-core QEMU VM: int main(int argc, char **argv) { pid_t pid, child; long nproc, i; /* ioprio_set(IOPRIO_WHO_PROCESS, 0, IOPRIO_PRIO_VALUE(IOPRIO_CLASS_IDLE, 0)); */ syscall(SYS_ioprio_set, 1, 0, 0x6000); nproc = sysconf(_SC_NPROCESSORS_ONLN); for (i = 0; i < nproc; i++) { pid = fork(); assert(pid != -1); if (pid == 0) { for (;;) { pid = fork(); assert(pid != -1); if (pid == 0) { _exit(0); } else { child = wait(NULL); assert(child == pid); } } } pid = fork(); assert(pid != -1); if (pid == 0) { for (;;) { /* ioprio_get(IOPRIO_WHO_PGRP, 0); */ syscall(SYS_ioprio_get, 2, 0); } } } for (;;) { /* ioprio_get(IOPRIO_WHO_PGRP, 0); */ syscall(SYS_ioprio_get, 2, 0); } return 0; } This gets us KASAN dumps like this: [ 35.526914] ================================================================== [ 35.530009] BUG: KASAN: out-of-bounds in get_task_ioprio+0x7b/0x90 at addr ffff880066f34e6c [ 35.530009] Read of size 2 by task ioprio-gpf/363 [ 35.530009] ============================================================================= [ 35.530009] BUG blkdev_ioc (Not tainted): kasan: bad access detected [ 35.530009] ----------------------------------------------------------------------------- [ 35.530009] Disabling lock debugging due to kernel taint [ 35.530009] INFO: Allocated in create_task_io_context+0x2b/0x370 age=0 cpu=0 pid=360 [ 35.530009] ___slab_alloc+0x55d/0x5a0 [ 35.530009] __slab_alloc.isra.20+0x2b/0x40 [ 35.530009] kmem_cache_alloc_node+0x84/0x200 [ 35.530009] create_task_io_context+0x2b/0x370 [ 35.530009] get_task_io_context+0x92/0xb0 [ 35.530009] copy_process.part.8+0x5029/0x5660 [ 35.530009] _do_fork+0x155/0x7e0 [ 35.530009] SyS_clone+0x19/0x20 [ 35.530009] do_syscall_64+0x195/0x3a0 [ 35.530009] return_from_SYSCALL_64+0x0/0x6a [ 35.530009] INFO: Freed in put_io_context+0xe7/0x120 age=0 cpu=0 pid=1060 [ 35.530009] __slab_free+0x27b/0x3d0 [ 35.530009] kmem_cache_free+0x1fb/0x220 [ 35.530009] put_io_context+0xe7/0x120 [ 35.530009] put_io_context_active+0x238/0x380 [ 35.530009] exit_io_context+0x66/0x80 [ 35.530009] do_exit+0x158e/0x2b90 [ 35.530009] do_group_exit+0xe5/0x2b0 [ 35.530009] SyS_exit_group+0x1d/0x20 [ 35.530009] entry_SYSCALL_64_fastpath+0x1a/0xa4 [ 35.530009] INFO: Slab 0xffffea00019bcd00 objects=20 used=4 fp=0xffff880066f34ff0 flags=0x1fffe0000004080 [ 35.530009] INFO: Object 0xffff880066f34e58 @offset=3672 fp=0x0000000000000001 [ 35.530009] ================================================================== Fix it by grabbing the task lock while we poke at the io_context. Change-Id: I4261aaf076fab943a80a45b0a77e023aa4ecbbd8 Cc: stable@vger.kernel.org Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* mnt: Fail collect_mounts when applied to unmounted mountsEric W. Biederman2016-11-171-2/+5
| | | | | | | | | | | | | | | | | | | | | | The only users of collect_mounts are in audit_tree.c In audit_trim_trees and audit_add_tree_rule the path passed into collect_mounts is generated from kern_path passed an audit_tree pathname which is guaranteed to be an absolute path. In those cases collect_mounts is obviously intended to work on mounted paths and if a race results in paths that are unmounted when collect_mounts it is reasonable to fail early. The paths passed into audit_tag_tree don't have the absolute path check. But are used to play with fsnotify and otherwise interact with the audit_trees, so again operating only on mounted paths appears reasonable. Avoid having to worry about what happens when we try and audit unmounted filesystems by restricting collect_mounts to mounts that appear in the mount tree. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
generated by cgit v1.2.3 (git 2.39.1) at 2026-04-03 03:59:31 +0000