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authorYang Yingliang <yangyingliang@huawei.com>2021-07-20 11:38:05 +0300
committerJens Axboe <axboe@kernel.dk>2021-07-20 16:51:47 +0300
commit362a9e65289284f36403058eea2462d0330c1f24 (patch)
tree0faeaed39500b370a3585c36ed36376f0a0f5eca /fs
parent46fee9ab02cb24979bbe07631fc3ae95ae08aa3e (diff)
downloadlinux-362a9e65289284f36403058eea2462d0330c1f24.tar.xz
io_uring: fix memleak in io_init_wq_offload()
I got memory leak report when doing fuzz test: BUG: memory leak unreferenced object 0xffff888107310a80 (size 96): comm "syz-executor.6", pid 4610, jiffies 4295140240 (age 20.135s) hex dump (first 32 bytes): 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N.......... backtrace: [<000000001974933b>] kmalloc include/linux/slab.h:591 [inline] [<000000001974933b>] kzalloc include/linux/slab.h:721 [inline] [<000000001974933b>] io_init_wq_offload fs/io_uring.c:7920 [inline] [<000000001974933b>] io_uring_alloc_task_context+0x466/0x640 fs/io_uring.c:7955 [<0000000039d0800d>] __io_uring_add_tctx_node+0x256/0x360 fs/io_uring.c:9016 [<000000008482e78c>] io_uring_add_tctx_node fs/io_uring.c:9052 [inline] [<000000008482e78c>] __do_sys_io_uring_enter fs/io_uring.c:9354 [inline] [<000000008482e78c>] __se_sys_io_uring_enter fs/io_uring.c:9301 [inline] [<000000008482e78c>] __x64_sys_io_uring_enter+0xabc/0xc20 fs/io_uring.c:9301 [<00000000b875f18f>] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [<00000000b875f18f>] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 [<000000006b0a8484>] entry_SYSCALL_64_after_hwframe+0x44/0xae CPU0 CPU1 io_uring_enter io_uring_enter io_uring_add_tctx_node io_uring_add_tctx_node __io_uring_add_tctx_node __io_uring_add_tctx_node io_uring_alloc_task_context io_uring_alloc_task_context io_init_wq_offload io_init_wq_offload hash = kzalloc hash = kzalloc ctx->hash_map = hash ctx->hash_map = hash <- one of the hash is leaked When calling io_uring_enter() in parallel, the 'hash_map' will be leaked, add uring_lock to protect 'hash_map'. Fixes: e941894eae31 ("io-wq: make buffered file write hashed work map per-ctx") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/20210720083805.3030730-1-yangyingliang@huawei.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs')
-rw-r--r--fs/io_uring.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 6486b54a0f62..fe3d948658ad 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -7905,15 +7905,19 @@ static struct io_wq *io_init_wq_offload(struct io_ring_ctx *ctx,
struct io_wq_data data;
unsigned int concurrency;
+ mutex_lock(&ctx->uring_lock);
hash = ctx->hash_map;
if (!hash) {
hash = kzalloc(sizeof(*hash), GFP_KERNEL);
- if (!hash)
+ if (!hash) {
+ mutex_unlock(&ctx->uring_lock);
return ERR_PTR(-ENOMEM);
+ }
refcount_set(&hash->refs, 1);
init_waitqueue_head(&hash->wait);
ctx->hash_map = hash;
}
+ mutex_unlock(&ctx->uring_lock);
data.hash = hash;
data.task = task;