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authorQian Cai <cai@lca.pw>2019-03-06 19:27:31 -0500
committerIngo Molnar <mingo@kernel.org>2019-03-09 14:15:52 +0100
commit69a106c00e8554a7e6b3f4bb2967332670f89337 (patch)
treed6b08cc1d4fc3428fb8bfaf65a5b62b11fd83b90 /kernel/workqueue.c
parent009bb421b6ceb7916ce627023d0eb7ced04c8910 (diff)
downloadlinux-69a106c00e8554a7e6b3f4bb2967332670f89337.tar.bz2
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@lca.pw> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: catalin.marinas@arm.com Cc: jiangshanlai@gmail.com Cc: tj@kernel.org Fixes: 669de8bda87b ("kernel/workqueue: Use dynamic lockdep keys for workqueues") Link: https://lkml.kernel.org/r/20190307002731.47371-1-cai@lca.pw Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/workqueue.c')
-rw-r--r--kernel/workqueue.c2
1 files changed, 2 insertions, 0 deletions
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);
}