Commit-ID: 69a106c00e8554a7e6b3f4bb2967332670f89337
Gitweb: https://git.kernel.org/tip/69a106c00e8554a7e6b3f4bb2967332670f89337
Author: Qian Cai <cai@xxxxxx>
AuthorDate: Wed, 6 Mar 2019 19:27:31 -0500
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Sat, 9 Mar 2019 14:15:52 +0100
workqueue, lockdep: Fix a memory leak in wq->lock_name
The following commit:
669de8bda87b ("kernel/workqueue: Use dynamic lockdep keys for workqueues")
introduced a memory leak as wq_free_lockdep() calls kfree(wq->lock_name),
but wq_init_lockdep() does not point wq->lock_name to the newly allocated
slab object.
This can be reproduced by running LTP fallocate04 followed by oom01 tests:
unreferenced object 0xc0000005876384d8 (size 64):
comm "fallocate04", pid 26972, jiffies 4297139141 (age 40370.480s)
hex dump (first 32 bytes):
28 77 71 5f 63 6f 6d 70 6c 65 74 69 6f 6e 29 65 (wq_completion)e
78 74 34 2d 72 73 76 2d 63 6f 6e 76 65 72 73 69 xt4-rsv-conversi
backtrace:
[<00000000cb452883>] kvasprintf+0x6c/0xe0
[<000000004654ddac>] kasprintf+0x34/0x60
[<000000001c68f311>] alloc_workqueue+0x1f8/0x6ac
[<0000000003c2ad83>] ext4_fill_super+0x23d4/0x3c80 [ext4]
[<0000000006610538>] mount_bdev+0x25c/0x290
[<00000000bcf955ec>] ext4_mount+0x28/0x50 [ext4]
[<0000000016e08fd3>] legacy_get_tree+0x4c/0xb0
[<0000000042b6a5fc>] vfs_get_tree+0x6c/0x190
[<00000000268ab022>] do_mount+0xb9c/0x1100
[<00000000698e6898>] ksys_mount+0x158/0x180
[<0000000064e391fd>] sys_mount+0x20/0x30
[<00000000ba378f12>] system_call+0x5c/0x70
Signed-off-by: Qian Cai <cai@xxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: catalin.marinas@xxxxxxx
Cc: jiangshanlai@xxxxxxxxx
Cc: tj@xxxxxxxxxx
Fixes: 669de8bda87b ("kernel/workqueue: Use dynamic lockdep keys for workqueues")
Link: https://lkml.kernel.org/r/20190307002731.47371-1-cai@xxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
kernel/workqueue.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index ecdd5e6f2166..e14da4f599ab 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -3348,6 +3348,8 @@ static void wq_init_lockdep(struct workqueue_struct *wq)
lock_name = kasprintf(GFP_KERNEL, "%s%s", "(wq_completion)", wq->name);
if (!lock_name)
lock_name = wq->name;
+
+ wq->lock_name = lock_name;
lockdep_init_map(&wq->lockdep_map, lock_name, &wq->key, 0);
}
|