The patch titled
Subject: ucounts: fix counter leak in inc_rlimit_get_ucounts()
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
ucounts-fix-counter-leak-in-inc_rlimit_get_ucounts.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/ucounts-fix-counter-leak-in-inc_rlimit_get_ucounts.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Andrei Vagin <avagin@xxxxxxxxxx>
Subject: ucounts: fix counter leak in inc_rlimit_get_ucounts()
Date: Fri, 1 Nov 2024 19:19:40 +0000
The inc_rlimit_get_ucounts() increments the specified rlimit counter and
then checks its limit. If the value exceeds the limit, the function
returns an error without decrementing the counter.
Link: https://lkml.kernel.org/r/20241101191940.3211128-1-roman.gushchin@xxxxxxxxx
Fixes: 15bc01effefe ("ucounts: Fix signal ucount refcounting")
Signed-off-by: Andrei Vagin <avagin@xxxxxxxxxx>
Co-developed-by: Roman Gushchin <roman.gushchin@xxxxxxxxx>
Signed-off-by: Roman Gushchin <roman.gushchin@xxxxxxxxx>
Tested-by: Roman Gushchin <roman.gushchin@xxxxxxxxx>
Acked-by: Alexey Gladkov <legion@xxxxxxxxxx>
Cc: Kees Cook <kees@xxxxxxxxxx>
Cc: Andrei Vagin <avagin@xxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Alexey Gladkov <legion@xxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/ucount.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
--- a/kernel/ucount.c~ucounts-fix-counter-leak-in-inc_rlimit_get_ucounts
+++ a/kernel/ucount.c
@@ -318,7 +318,7 @@ long inc_rlimit_get_ucounts(struct ucoun
for (iter = ucounts; iter; iter = iter->ns->ucounts) {
long new = atomic_long_add_return(1, &iter->rlimit[type]);
if (new < 0 || (!override_rlimit && (new > max)))
- goto unwind;
+ goto dec_unwind;
if (iter == ucounts)
ret = new;
max = get_userns_rlimit_max(iter->ns, type);
@@ -335,7 +335,6 @@ long inc_rlimit_get_ucounts(struct ucoun
dec_unwind:
dec = atomic_long_sub_return(1, &iter->rlimit[type]);
WARN_ON_ONCE(dec < 0);
-unwind:
do_dec_rlimit_put_ucounts(ucounts, iter, type);
return 0;
}
_
Patches currently in -mm which might be from avagin@xxxxxxxxxx are
ucounts-fix-counter-leak-in-inc_rlimit_get_ucounts.patch
