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| author | Eric W. Biederman <ebiederm@xmission.com> | 2020-04-02 18:04:54 -0500 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2020-05-07 16:55:47 -0500 |
| commit | 89826cce37542f7950e8f4b9258284805e98430c (patch) | |
| tree | 6c56c7eed4eb0022a707cbd9b4d648440565bad7 | |
| parent | e7f7785449a1f459a4a3ca92f82f56fb054dd2b9 (diff) | |
| download | linux-stable-89826cce37542f7950e8f4b9258284805e98430c.tar.gz linux-stable-89826cce37542f7950e8f4b9258284805e98430c.tar.bz2 linux-stable-89826cce37542f7950e8f4b9258284805e98430c.zip | |
exec: Make unlocking exec_update_mutex explict
With install_exec_creds updated to follow immediately after
setup_new_exec, the failure of unshare_sighand is the only
code path where exec_update_mutex is held but not explicitly
unlocked.
Update that code path to explicitly unlock exec_update_mutex.
Remove the unlocking of exec_update_mutex from free_bprm.
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Greg Ungerer <gerg@linux-m68k.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
| -rw-r--r-- | fs/exec.c | 6 | ||||
| -rw-r--r-- | include/linux/binfmts.h | 3 |
2 files changed, 4 insertions, 5 deletions
diff --git a/fs/exec.c b/fs/exec.c index 06b4c550af5d..6bd82a007bfc 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1344,7 +1344,7 @@ int flush_old_exec(struct linux_binprm * bprm) */ retval = unshare_sighand(me); if (retval) - goto out; + goto out_unlock; set_fs(USER_DS); me->flags &= ~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD | @@ -1361,6 +1361,8 @@ int flush_old_exec(struct linux_binprm * bprm) do_close_on_exec(me->files); return 0; +out_unlock: + mutex_unlock(&me->signal->exec_update_mutex); out: return retval; } @@ -1477,8 +1479,6 @@ static void free_bprm(struct linux_binprm *bprm) { free_arg_pages(bprm); if (bprm->cred) { - if (bprm->called_exec_mmap) - mutex_unlock(¤t->signal->exec_update_mutex); mutex_unlock(¤t->signal->cred_guard_mutex); abort_creds(bprm->cred); } diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h index a345d9fed3d8..6f564b9ad882 100644 --- a/include/linux/binfmts.h +++ b/include/linux/binfmts.h @@ -47,8 +47,7 @@ struct linux_binprm { secureexec:1, /* * Set by flush_old_exec, when exec_mmap has been called. - * This is past the point of no return, when the - * exec_update_mutex has been taken. + * This is past the point of no return. */ called_exec_mmap:1; #ifdef __alpha__ |