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-rw-r--r--kernel/events/core.c6
-rw-r--r--kernel/futex.c7
-rw-r--r--kernel/futex_compat.c2
-rw-r--r--kernel/kcmp.c4
-rw-r--r--kernel/module.c26
-rw-r--r--kernel/ptrace.c39
6 files changed, 60 insertions, 24 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index d9b0aad17..0f5207839 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -2938,7 +2938,7 @@ find_lively_task_by_vpid(pid_t vpid)
/* Reuse ptrace permission checks for now. */
err = -EACCES;
- if (!ptrace_may_access(task, PTRACE_MODE_READ))
+ if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS))
goto errout;
return task;
@@ -5639,6 +5639,10 @@ static int perf_tp_filter_match(struct perf_event *event,
{
void *record = data->raw->data;
+ /* only top level events have filters set */
+ if (event->parent)
+ event = event->parent;
+
if (likely(!event->filter) || filter_match_preds(event->filter, record))
return 1;
return 0;
diff --git a/kernel/futex.c b/kernel/futex.c
index ad971d0f0..fea18acbe 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -2495,6 +2495,11 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
if (q.pi_state && (q.pi_state->owner != current)) {
spin_lock(q.lock_ptr);
ret = fixup_pi_state_owner(uaddr2, &q, current);
+ /*
+ * Drop the reference to the pi state which
+ * the requeue_pi() code acquired for us.
+ */
+ free_pi_state(q.pi_state);
spin_unlock(q.lock_ptr);
}
} else {
@@ -2621,7 +2626,7 @@ SYSCALL_DEFINE3(get_robust_list, int, pid,
}
ret = -EPERM;
- if (!ptrace_may_access(p, PTRACE_MODE_READ))
+ if (!ptrace_may_access(p, PTRACE_MODE_READ_REALCREDS))
goto err_unlock;
head = p->robust_list;
diff --git a/kernel/futex_compat.c b/kernel/futex_compat.c
index f9f44fd4d..3888617a1 100644
--- a/kernel/futex_compat.c
+++ b/kernel/futex_compat.c
@@ -155,7 +155,7 @@ COMPAT_SYSCALL_DEFINE3(get_robust_list, int, pid,
}
ret = -EPERM;
- if (!ptrace_may_access(p, PTRACE_MODE_READ))
+ if (!ptrace_may_access(p, PTRACE_MODE_READ_REALCREDS))
goto err_unlock;
head = p->compat_robust_list;
diff --git a/kernel/kcmp.c b/kernel/kcmp.c
index 0aa69ea1d..3a47fa998 100644
--- a/kernel/kcmp.c
+++ b/kernel/kcmp.c
@@ -122,8 +122,8 @@ SYSCALL_DEFINE5(kcmp, pid_t, pid1, pid_t, pid2, int, type,
&task2->signal->cred_guard_mutex);
if (ret)
goto err;
- if (!ptrace_may_access(task1, PTRACE_MODE_READ) ||
- !ptrace_may_access(task2, PTRACE_MODE_READ)) {
+ if (!ptrace_may_access(task1, PTRACE_MODE_READ_REALCREDS) ||
+ !ptrace_may_access(task2, PTRACE_MODE_READ_REALCREDS)) {
ret = -EPERM;
goto err_unlock;
}
diff --git a/kernel/module.c b/kernel/module.c
index b0243db17..57085deed 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3398,6 +3398,11 @@ static inline int is_arm_mapping_symbol(const char *str)
&& (str[2] == '\0' || str[2] == '.');
}
+static const char *symname(struct module *mod, unsigned int symnum)
+{
+ return mod->strtab + mod->symtab[symnum].st_name;
+}
+
static const char *get_ksymbol(struct module *mod,
unsigned long addr,
unsigned long *size,
@@ -3420,15 +3425,15 @@ static const char *get_ksymbol(struct module *mod,
/* We ignore unnamed symbols: they're uninformative
* and inserted at a whim. */
+ if (*symname(mod, i) == '\0'
+ || is_arm_mapping_symbol(symname(mod, i)))
+ continue;
+
if (mod->symtab[i].st_value <= addr
- && mod->symtab[i].st_value > mod->symtab[best].st_value
- && *(mod->strtab + mod->symtab[i].st_name) != '\0'
- && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
+ && mod->symtab[i].st_value > mod->symtab[best].st_value)
best = i;
if (mod->symtab[i].st_value > addr
- && mod->symtab[i].st_value < nextval
- && *(mod->strtab + mod->symtab[i].st_name) != '\0'
- && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
+ && mod->symtab[i].st_value < nextval)
nextval = mod->symtab[i].st_value;
}
@@ -3439,7 +3444,7 @@ static const char *get_ksymbol(struct module *mod,
*size = nextval - mod->symtab[best].st_value;
if (offset)
*offset = addr - mod->symtab[best].st_value;
- return mod->strtab + mod->symtab[best].st_name;
+ return symname(mod, best);
}
/* For kallsyms to ask for address resolution. NULL means not found. Careful
@@ -3540,8 +3545,7 @@ int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
if (symnum < mod->num_symtab) {
*value = mod->symtab[symnum].st_value;
*type = mod->symtab[symnum].st_info;
- strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
- KSYM_NAME_LEN);
+ strlcpy(name, symname(mod, symnum), KSYM_NAME_LEN);
strlcpy(module_name, mod->name, MODULE_NAME_LEN);
*exported = is_exported(name, *value, mod);
preempt_enable();
@@ -3558,7 +3562,7 @@ static unsigned long mod_find_symname(struct module *mod, const char *name)
unsigned int i;
for (i = 0; i < mod->num_symtab; i++)
- if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
+ if (strcmp(name, symname(mod, i)) == 0 &&
mod->symtab[i].st_info != 'U')
return mod->symtab[i].st_value;
return 0;
@@ -3602,7 +3606,7 @@ int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
if (mod->state == MODULE_STATE_UNFORMED)
continue;
for (i = 0; i < mod->num_symtab; i++) {
- ret = fn(data, mod->strtab + mod->symtab[i].st_name,
+ ret = fn(data, symname(mod, i),
mod, mod->symtab[i].st_value);
if (ret != 0)
return ret;
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 30ab20623..72b0b3e0e 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -225,6 +225,14 @@ static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode)
static int __ptrace_may_access(struct task_struct *task, unsigned int mode)
{
const struct cred *cred = current_cred(), *tcred;
+ int dumpable = 0;
+ kuid_t caller_uid;
+ kgid_t caller_gid;
+
+ if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) {
+ WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n");
+ return -EPERM;
+ }
/* May we inspect the given task?
* This check is used both for attaching with ptrace
@@ -234,18 +242,33 @@ static int __ptrace_may_access(struct task_struct *task, unsigned int mode)
* because setting up the necessary parent/child relationship
* or halting the specified task is impossible.
*/
- int dumpable = 0;
+
/* Don't let security modules deny introspection */
if (same_thread_group(task, current))
return 0;
rcu_read_lock();
+ if (mode & PTRACE_MODE_FSCREDS) {
+ caller_uid = cred->fsuid;
+ caller_gid = cred->fsgid;
+ } else {
+ /*
+ * Using the euid would make more sense here, but something
+ * in userland might rely on the old behavior, and this
+ * shouldn't be a security problem since
+ * PTRACE_MODE_REALCREDS implies that the caller explicitly
+ * used a syscall that requests access to another process
+ * (and not a filesystem syscall to procfs).
+ */
+ caller_uid = cred->uid;
+ caller_gid = cred->gid;
+ }
tcred = __task_cred(task);
- if (uid_eq(cred->uid, tcred->euid) &&
- uid_eq(cred->uid, tcred->suid) &&
- uid_eq(cred->uid, tcred->uid) &&
- gid_eq(cred->gid, tcred->egid) &&
- gid_eq(cred->gid, tcred->sgid) &&
- gid_eq(cred->gid, tcred->gid))
+ if (uid_eq(caller_uid, tcred->euid) &&
+ uid_eq(caller_uid, tcred->suid) &&
+ uid_eq(caller_uid, tcred->uid) &&
+ gid_eq(caller_gid, tcred->egid) &&
+ gid_eq(caller_gid, tcred->sgid) &&
+ gid_eq(caller_gid, tcred->gid))
goto ok;
if (ptrace_has_cap(tcred->user_ns, mode))
goto ok;
@@ -312,7 +335,7 @@ static int ptrace_attach(struct task_struct *task, long request,
goto out;
task_lock(task);
- retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH);
+ retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS);
task_unlock(task);
if (retval)
goto unlock_creds;
generated by cgit v1.2.3 (git 2.39.1) at 2026-03-14 10:19:24 +0000