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authorRafael Mendonca <rafaelmendsr@gmail.com>2022-10-20 04:47:09 +0300
committerJens Axboe <axboe@kernel.dk>2022-10-20 15:48:59 +0300
commit996d3efeb091c503afd3ee6b5e20eabf446fd955 (patch)
tree187f45814eade85a8548fb61e20eda6652344bf1
parent16bbdfe5fb0e78e0acb13e45fc127e9a296913f2 (diff)
downloadlinux-996d3efeb091c503afd3ee6b5e20eabf446fd955.tar.xz
io-wq: Fix memory leak in worker creation
If the CPU mask allocation for a node fails, then the memory allocated for the 'io_wqe' struct of the current node doesn't get freed on the error handling path, since it has not yet been added to the 'wqes' array. This was spotted when fuzzing v6.1-rc1 with Syzkaller: BUG: memory leak unreferenced object 0xffff8880093d5000 (size 1024): comm "syz-executor.2", pid 7701, jiffies 4295048595 (age 13.900s) 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: [<00000000cb463369>] __kmem_cache_alloc_node+0x18e/0x720 [<00000000147a3f9c>] kmalloc_node_trace+0x2a/0x130 [<000000004e107011>] io_wq_create+0x7b9/0xdc0 [<00000000c38b2018>] io_uring_alloc_task_context+0x31e/0x59d [<00000000867399da>] __io_uring_add_tctx_node.cold+0x19/0x1ba [<000000007e0e7a79>] io_uring_setup.cold+0x1b80/0x1dce [<00000000b545e9f6>] __x64_sys_io_uring_setup+0x5d/0x80 [<000000008a8a7508>] do_syscall_64+0x5d/0x90 [<000000004ac08bec>] entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: 0e03496d1967 ("io-wq: use private CPU mask") Cc: stable@vger.kernel.org Signed-off-by: Rafael Mendonca <rafaelmendsr@gmail.com> Link: https://lore.kernel.org/r/20221020014710.902201-1-rafaelmendsr@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--io_uring/io-wq.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/io_uring/io-wq.c b/io_uring/io-wq.c
index c6536d4b2da0..6f1d0e5df23a 100644
--- a/io_uring/io-wq.c
+++ b/io_uring/io-wq.c
@@ -1164,10 +1164,10 @@ struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data)
wqe = kzalloc_node(sizeof(struct io_wqe), GFP_KERNEL, alloc_node);
if (!wqe)
goto err;
+ wq->wqes[node] = wqe;
if (!alloc_cpumask_var(&wqe->cpu_mask, GFP_KERNEL))
goto err;
cpumask_copy(wqe->cpu_mask, cpumask_of_node(node));
- wq->wqes[node] = wqe;
wqe->node = alloc_node;
wqe->acct[IO_WQ_ACCT_BOUND].max_workers = bounded;
wqe->acct[IO_WQ_ACCT_UNBOUND].max_workers =