diff mbox series

[SRU,Jammy-OEM-5.17/OEM-6.0,1/1] prlimit: do_prlimit needs to have a speculation check

Message ID 20230731145003.13459-2-yuxuan.luo@canonical.com
State New
Headers show
Series CVE-2023-0458 | expand

Commit Message

Yuxuan Luo July 31, 2023, 2:50 p.m. UTC 
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

do_prlimit() adds the user-controlled resource value to a pointer that
will subsequently be dereferenced.  In order to help prevent this
codepath from being used as a spectre "gadget" a barrier needs to be
added after checking the range.

Reported-by: Jordy Zomer <jordyzomer@google.com>
Tested-by: Jordy Zomer <jordyzomer@google.com>
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 739790605705ddcf18f21782b9c99ad7d53a8c11)
CVE-2023-0458
Signed-off-by: Yuxuan Luo <yuxuan.luo@canonical.com>
---
 kernel/sys.c | 2 ++
 1 file changed, 2 insertions(+)
diff mbox series

Patch

diff --git a/kernel/sys.c b/kernel/sys.c
index 1452780c2aff..dc4857fb1b60 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1454,6 +1454,8 @@  static int do_prlimit(struct task_struct *tsk, unsigned int resource,
 
 	if (resource >= RLIM_NLIMITS)
 		return -EINVAL;
+	resource = array_index_nospec(resource, RLIM_NLIMITS);
+
 	if (new_rlim) {
 		if (new_rlim->rlim_cur > new_rlim->rlim_max)
 			return -EINVAL;