luck/tmp_suning_uos_patched
1
0
Fork 1
Code Issues Pull Requests Packages Projects Releases Wiki Activity

openat2: reject RESOLVE_BENEATH|RESOLVE_IN_ROOT

Browse Source 
commit 398840f8bb935d33c64df4ec4fed77a7d24c267d upstream.

This was an oversight in the original implementation, as it makes no
sense to specify both scoping flags to the same openat2(2) invocation
(before this patch, the result of such an invocation was equivalent to
RESOLVE_IN_ROOT being ignored).

This is a userspace-visible ABI change, but the only user of openat2(2)
at the moment is LXC which doesn't specify both flags and so no
userspace programs will break as a result.

Fixes: fddb5d430a ("open: introduce openat2(2) syscall")
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: <stable@vger.kernel.org> # v5.6+
Link: https://lore.kernel.org/r/20201027235044.5240-2-cyphar@cyphar.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Aleksa Sarai 2020-10-28 10:50:43 +11:00 committed by Greg Kroah-Hartman
parent da65881cec
commit aa606ebab1
1 changed files with 4 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
fs/open.c
View File

@ -1010,6 +1010,10 @@ inline int build_open_flags(const struct open_how *how, struct open_flags *op)
if (how->resolve & ~VALID_RESOLVE_FLAGS)
return -EINVAL;
/* Scoping flags are mutually exclusive. */
if ((how->resolve & RESOLVE_BENEATH) && (how->resolve & RESOLVE_IN_ROOT))
return -EINVAL;
/* Deal with the mode. */
if (WILL_CREATE(flags)) {
if (how->mode & ~S_IALLUGO)