aboutsummaryrefslogtreecommitdiff
path: root/fs/exec.c
Commit message (Collapse)AuthorAgeFilesLines
* fs/exec.c: account for argv/envp pointersKees Cook2017-07-041-4/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 98da7d08850fb8bdeb395d6368ed15753304aa0c upstream. When limiting the argv/envp strings during exec to 1/4 of the stack limit, the storage of the pointers to the strings was not included. This means that an exec with huge numbers of tiny strings could eat 1/4 of the stack limit in strings and then additional space would be later used by the pointers to the strings. For example, on 32-bit with a 8MB stack rlimit, an exec with 1677721 single-byte strings would consume less than 2MB of stack, the max (8MB / 4) amount allowed, but the pointers to the strings would consume the remaining additional stack space (1677721 * 4 == 6710884). The result (1677721 + 6710884 == 8388605) would exhaust stack space entirely. Controlling this stack exhaustion could result in pathological behavior in setuid binaries (CVE-2017-1000365). [akpm@linux-foundation.org: additional commenting from Kees] Fixes: b6a2fea39318 ("mm: variable length argument support") Link: http://lkml.kernel.org/r/20170622001720.GA32173@beast Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Qualys Security Advisory <qsa@qualys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Change-Id: I2e01d7be2d52415264ff48c632bfe307008c4e03
* uksm: remove Mtk aksm & uksm (because its fugly)Mister Oyster2017-07-041-3/+2
| | | | | | | | | | | | | | | | Revert "KSM: mediatek: implement Adaptive KSM" Revert "mm: uksm: fix maybe-uninitialized warning" Revert "UKSM: Add Governors for Higher CPU usage (HighCPU) for more merging, and low cpu usage (Battery) for less battery drain" Revert "uksm: use deferrable timer" Revert "mm: limit UKSM sleep time instead of failing" Revert "uksm: Fix warning" Revert "uksm: clean up and remove some (no)inlines" Revert "uksm: modify ema logic and tidy up" Revert "uksm: enhancements and cleanups" Revert "uksm: squashed fixups" Revert "UKSM: cast variable as const" Revert "UKSM: remove U64_MAX definition" Revert "add uksm 0.1.2.3 for v3.10 .ge.46.patch"
* fs: exec: apply CLOEXEC before changing dumpable task flagsAleksa Sarai2017-06-171-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 613cc2b6f272c1a8ad33aefa21cad77af23139f7 upstream. If you have a process that has set itself to be non-dumpable, and it then undergoes exec(2), any CLOEXEC file descriptors it has open are "exposed" during a race window between the dumpable flags of the process being reset for exec(2) and CLOEXEC being applied to the file descriptors. This can be exploited by a process by attempting to access /proc/<pid>/fd/... during this window, without requiring CAP_SYS_PTRACE. The race in question is after set_dumpable has been (for get_link, though the trace is basically the same for readlink): [vfs] -> proc_pid_link_inode_operations.get_link -> proc_pid_get_link -> proc_fd_access_allowed -> ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS); Which will return 0, during the race window and CLOEXEC file descriptors will still be open during this window because do_close_on_exec has not been called yet. As a result, the ordering of these calls should be reversed to avoid this race window. This is of particular concern to container runtimes, where joining a PID namespace with file descriptors referring to the host filesystem can result in security issues (since PRCTL_SET_DUMPABLE doesn't protect against access of CLOEXEC file descriptors -- file descriptors which may reference filesystem objects the container shouldn't have access to). Cc: dev@opencontainers.org Reported-by: Michael Crosby <crosbymichael@gmail.com> Signed-off-by: Aleksa Sarai <asarai@suse.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
* kernel: Only expose su when daemon is runningTom Marshall2017-05-211-0/+5
| | | | | | | | | | | | | | It has been claimed that the PG implementation of 'su' has security vulnerabilities even when disabled. Unfortunately, the people that find these vulnerabilities often like to keep them private so they can profit from exploits while leaving users exposed to malicious hackers. In order to reduce the attack surface for vulnerabilites, it is therefore necessary to make 'su' completely inaccessible when it is not in use (except by the root and system users). Change-Id: I79716c72f74d0b7af34ec3a8054896c6559a181d
* vfs: Add permission2 for filesystems with per mount permissionsDaniel Rosenberg2017-04-131-1/+1
| | | | | | | | | | This allows filesystems to use their mount private data to influence the permssions they return in permission2. It has been separated into a new call to avoid disrupting current permission users. Change-Id: I9d416e3b8b6eca84ef3e336bd2af89ddd51df6ca Signed-off-by: Daniel Rosenberg <drosen@google.com>
* fs: support task's adj rbtreeYi-wei Zhao2017-04-111-0/+7
| | | | | | | | | | | | | Add (or del) a task to (or from) task's adj rbtree when its oom_score_adj is modified. Change-Id: I8a9490c6f30f42f6e4ed8f7fa9249f6da6177ae2 Signed-off-by: Hong-Mei Li <a21834@motorola.com> Signed-off-by: Yi-wei Zhao <gbjc64@motorola.com> Reviewed-on: http://gerrit.mot.com/701206 SLTApproved: Slta Waiver <sltawvr@motorola.com> Tested-by: Jira Key <jirakey@motorola.com> Submit-Approved: Jira Key <jirakey@motorola.com>
* add uksm 0.1.2.3 for v3.10 .ge.46.patchLevin Calado2016-08-261-2/+3
| | | | | | | Conflicts: fs/exec.c Signed-off-by: Stefan Guendhoer <stefan@guendhoer.com>
* fs: fix commit 9eae8ac6 based off d0ff694Levin Calado2016-08-261-1/+1
| | | | | Signed-off-by: Levin Calado <levincalado@gmail.com> Signed-off-by: Stefan Guendhoer <stefan@guendhoer.com>
* fs: take i_mutex during prepare_binprm for set[ug]id executablesJann Horn2016-08-261-28/+48
| | | | | | | | | | | | | | | | | | commit 8b01fc86b9f425899f8a3a8fc1c47d73c2c20543 upstream. This prevents a race between chown() and execve(), where chowning a setuid-user binary to root would momentarily make the binary setuid root. This patch was mostly written by Linus Torvalds. Signed-off-by: Jann Horn <jann@thejh.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Charles Williams <ciwillia@brocade.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Sheng Yong <shengyong1@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Stefan Guendhoer <stefan@guendhoer.com>
* first commitMeizu OpenSource2016-08-151-0/+1709