The patch titled
Subject: fs/proc/proc_sysctl.c: fix potential page fault while unregistering sysctl table
has been added to the -mm tree. Its filename is
fs-sysctl-fix-potential-page-fault-while-unregistering-sysctl-table.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/fs-sysctl-fix-potential-page-fault-while-unregistering-sysctl-table.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/fs-sysctl-fix-potential-page-fault-while-unregistering-sysctl-table.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Danilo Krummrich <danilokrummrich@xxxxxxxxxxxxx>
Subject: fs/proc/proc_sysctl.c: fix potential page fault while unregistering sysctl table
proc_sys_link_fill_cache() does not take currently unregistering sysctl
tables into account, which might result into a page fault in
sysctl_follow_link() - add a check to fix it.
This bug has been present since v3.4.
Link: http://lkml.kernel.org/r/20180228013506.4915-1-danilokrummrich@xxxxxxxxxxxxx
Fixes: 0e47c99d7fe25 ("sysctl: Replace root_list with links between sysctl_table_sets")
Signed-off-by: Danilo Krummrich <danilokrummrich@xxxxxxxxxxxxx>
Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: "Luis R . Rodriguez" <mcgrof@xxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/proc/proc_sysctl.c | 3 +++
1 file changed, 3 insertions(+)
diff -puN fs/proc/proc_sysctl.c~fs-sysctl-fix-potential-page-fault-while-unregistering-sysctl-table fs/proc/proc_sysctl.c
--- a/fs/proc/proc_sysctl.c~fs-sysctl-fix-potential-page-fault-while-unregistering-sysctl-table
+++ a/fs/proc/proc_sysctl.c
@@ -707,7 +707,10 @@ static bool proc_sys_link_fill_cache(str
struct ctl_table *table)
{
bool ret = true;
+
head = sysctl_head_grab(head);
+ if (IS_ERR(head))
+ return false;
if (S_ISLNK(table->mode)) {
/* It is not an error if we can not follow the link ignore it */
_
Patches currently in -mm which might be from danilokrummrich@xxxxxxxxxxxxx are
fs-sysctl-fix-potential-page-fault-while-unregistering-sysctl-table.patch
fs-sysctl-remove-redundant-link-check-in-proc_sys_link_fill_cache.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
