diff options
| author | Jesper Nilsson <jesper.nilsson@axis.com> | 2013-11-21 14:32:08 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-11-29 11:11:41 -0800 |
| commit | c6cac65e0d07f9a4c57b68702db945db6e0321f7 (patch) | |
| tree | 92b0d7b4837ac3f19c8af586989520924abf8073 /ipc | |
| parent | ef1c63283fc95d0e60904937f5a428cc2c9236bd (diff) | |
ipc,shm: correct error return value in shmctl (SHM_UNLOCK)
commit 3a72660b07d86d60457ca32080b1ce8c2b628ee2 upstream.
Commit 2caacaa82a51 ("ipc,shm: shorten critical region for shmctl")
restructured the ipc shm to shorten critical region, but introduced a
path where the return value could be -EPERM, even if the operation
actually was performed.
Before the commit, the err return value was reset by the return value
from security_shm_shmctl() after the if (!ns_capable(...)) statement.
Now, we still exit the if statement with err set to -EPERM, and in the
case of SHM_UNLOCK, it is not reset at all, and used as the return value
from shmctl.
To fix this, we only set err when errors occur, leaving the fallthrough
case alone.
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Davidlohr Bueso <davidlohr@hp.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Michel Lespinasse <walken@google.com>
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'ipc')
| -rw-r--r-- | ipc/shm.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/ipc/shm.c b/ipc/shm.c index 7b87bea5245b..8ffae5807317 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -974,12 +974,15 @@ SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf) ipc_lock_object(&shp->shm_perm); if (!ns_capable(ns->user_ns, CAP_IPC_LOCK)) { kuid_t euid = current_euid(); - err = -EPERM; if (!uid_eq(euid, shp->shm_perm.uid) && - !uid_eq(euid, shp->shm_perm.cuid)) + !uid_eq(euid, shp->shm_perm.cuid)) { + err = -EPERM; goto out_unlock0; - if (cmd == SHM_LOCK && !rlimit(RLIMIT_MEMLOCK)) + } + if (cmd == SHM_LOCK && !rlimit(RLIMIT_MEMLOCK)) { + err = -EPERM; goto out_unlock0; + } } shm_file = shp->shm_file; |