The patch titled
Subject: tmpfs: fix mempolicy object leaks
has been added to the -mm tree. Its filename is
tmpfs-fix-mempolicy-object-leaks.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: Greg Thelen <gthelen@xxxxxxxxxx>
Subject: tmpfs: fix mempolicy object leaks
Fix several mempolicy leaks in the tmpfs mount logic. These leaks are
slow - on the order of one object leaked per mount attempt.
Leak 1 (umount doesn't free mpol allocated in mount):
while true; do
mount -t tmpfs -o mpol=interleave,size=100M nodev /mnt
umount /mnt
done
Leak 2 (errors parsing remount options will leak mpol):
mount -t tmpfs -o size=100M nodev /mnt
while true; do
mount -o remount,mpol=interleave,size=x /mnt 2> /dev/null
done
umount /mnt
Leak 3 (multiple mpol per mount leak mpol):
while true; do
mount -t tmpfs -o mpol=interleave,mpol=interleave,size=100M nodev /mnt
umount /mnt
done
This patch fixes all of the above. I could have broken the patch into
three pieces but is seemed easier to review as one.
Signed-off-by: Greg Thelen <gthelen@xxxxxxxxxx>
Acked-by: Hugh Dickins <hughd@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/shmem.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff -puN mm/shmem.c~tmpfs-fix-mempolicy-object-leaks mm/shmem.c
--- a/mm/shmem.c~tmpfs-fix-mempolicy-object-leaks
+++ a/mm/shmem.c
@@ -2385,6 +2385,7 @@ static int shmem_parse_options(char *opt
bool remount)
{
char *this_char, *value, *rest;
+ struct mempolicy *mpol = NULL;
uid_t uid;
gid_t gid;
@@ -2413,7 +2414,7 @@ static int shmem_parse_options(char *opt
printk(KERN_ERR
"tmpfs: No value for mount option '%s'\n",
this_char);
- return 1;
+ goto error;
}
if (!strcmp(this_char,"size")) {
@@ -2462,19 +2463,23 @@ static int shmem_parse_options(char *opt
if (!gid_valid(sbinfo->gid))
goto bad_val;
} else if (!strcmp(this_char,"mpol")) {
- if (mpol_parse_str(value, &sbinfo->mpol))
+ mpol_put(mpol);
+ if (mpol_parse_str(value, &mpol))
goto bad_val;
} else {
printk(KERN_ERR "tmpfs: Bad mount option %s\n",
this_char);
- return 1;
+ goto error;
}
}
+ sbinfo->mpol = mpol;
return 0;
bad_val:
printk(KERN_ERR "tmpfs: Bad value '%s' for mount option '%s'\n",
value, this_char);
+error:
+ mpol_put(mpol);
return 1;
}
@@ -2550,6 +2555,7 @@ static void shmem_put_super(struct super
struct shmem_sb_info *sbinfo = SHMEM_SB(sb);
percpu_counter_destroy(&sbinfo->used_blocks);
+ mpol_put(sbinfo->mpol);
kfree(sbinfo);
sb->s_fs_info = NULL;
}
_
Patches currently in -mm which might be from gthelen@xxxxxxxxxx are
origin.patch
linux-next.patch
memcg-reduce-the-size-of-struct-memcg-244-fold.patch
memcg-reduce-the-size-of-struct-memcg-244-fold-fix.patch
tmpfs-fix-use-after-free-of-mempolicy-object.patch
tmpfs-fix-mempolicy-object-leaks.patch
tmpfs-fix-mempolicy-object-leaks-fix.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
