This is a note to let you know that I've just added the patch titled
ubifs: Fix memory leak in alloc_wbufs()
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ubifs-fix-memory-leak-in-alloc_wbufs.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 1dfd4b5bc6ecc5f5b8482f7ed43edae65ad7370d
Author: Li Zetao <lizetao1@xxxxxxxxxx>
Date: Sat Oct 22 19:52:11 2022 +0800
ubifs: Fix memory leak in alloc_wbufs()
[ Upstream commit 4a1ff3c5d04b9079b4f768d9a71b51c4af578dd2 ]
kmemleak reported a sequence of memory leaks, and show them as following:
unreferenced object 0xffff8881575f8400 (size 1024):
comm "mount", pid 19625, jiffies 4297119604 (age 20.383s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff8176cecd>] __kmalloc+0x4d/0x150
[<ffffffffa0406b2b>] ubifs_mount+0x307b/0x7170 [ubifs]
[<ffffffff819fa8fd>] legacy_get_tree+0xed/0x1d0
[<ffffffff81936f2d>] vfs_get_tree+0x7d/0x230
[<ffffffff819b2bd4>] path_mount+0xdd4/0x17b0
[<ffffffff819b37aa>] __x64_sys_mount+0x1fa/0x270
[<ffffffff83c14295>] do_syscall_64+0x35/0x80
[<ffffffff83e0006a>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
unreferenced object 0xffff8881798a6e00 (size 512):
comm "mount", pid 19677, jiffies 4297121912 (age 37.816s)
hex dump (first 32 bytes):
6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
backtrace:
[<ffffffff8176cecd>] __kmalloc+0x4d/0x150
[<ffffffffa0418342>] ubifs_wbuf_init+0x52/0x480 [ubifs]
[<ffffffffa0406ca5>] ubifs_mount+0x31f5/0x7170 [ubifs]
[<ffffffff819fa8fd>] legacy_get_tree+0xed/0x1d0
[<ffffffff81936f2d>] vfs_get_tree+0x7d/0x230
[<ffffffff819b2bd4>] path_mount+0xdd4/0x17b0
[<ffffffff819b37aa>] __x64_sys_mount+0x1fa/0x270
[<ffffffff83c14295>] do_syscall_64+0x35/0x80
[<ffffffff83e0006a>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
The problem is that the ubifs_wbuf_init() returns an error in the
loop which in the alloc_wbufs(), then the wbuf->buf and wbuf->inodes
that were successfully alloced before are not freed.
Fix it by adding error hanging path in alloc_wbufs() which frees
the memory alloced before when ubifs_wbuf_init() returns an error.
Fixes: 1e51764a3c2a ("UBIFS: add new flash file system")
Signed-off-by: Li Zetao <lizetao1@xxxxxxxxxx>
Reviewed-by: Zhihao Cheng <chengzhihao1@xxxxxxxxxx>
Signed-off-by: Richard Weinberger <richard@xxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 6a8f9efc2e2f0..1df193c87e920 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -833,7 +833,7 @@ static int alloc_wbufs(struct ubifs_info *c)
INIT_LIST_HEAD(&c->jheads[i].buds_list);
err = ubifs_wbuf_init(c, &c->jheads[i].wbuf);
if (err)
- return err;
+ goto out_wbuf;
c->jheads[i].wbuf.sync_callback = &bud_wbuf_callback;
c->jheads[i].wbuf.jhead = i;
@@ -841,7 +841,7 @@ static int alloc_wbufs(struct ubifs_info *c)
c->jheads[i].log_hash = ubifs_hash_get_desc(c);
if (IS_ERR(c->jheads[i].log_hash)) {
err = PTR_ERR(c->jheads[i].log_hash);
- goto out;
+ goto out_log_hash;
}
}
@@ -854,9 +854,18 @@ static int alloc_wbufs(struct ubifs_info *c)
return 0;
-out:
- while (i--)
+out_log_hash:
+ kfree(c->jheads[i].wbuf.buf);
+ kfree(c->jheads[i].wbuf.inodes);
+
+out_wbuf:
+ while (i--) {
+ kfree(c->jheads[i].wbuf.buf);
+ kfree(c->jheads[i].wbuf.inodes);
kfree(c->jheads[i].log_hash);
+ }
+ kfree(c->jheads);
+ c->jheads = NULL;
return err;
}
