| Message ID | 20221031031242.94107-1-chenjun102@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | blk-mq: Fix kmemleak in blk_mq_init_allocated_queue | expand |
On Mon, Oct 31, 2022 at 03:12:42AM +0000, Chen Jun wrote: > There is a kmemleak caused by modprobe null_blk.ko > > unreferenced object 0xffff8881acb1f000 (size 1024): > comm "modprobe", pid 836, jiffies 4294971190 (age 27.068s) > hex dump (first 32 bytes): > 00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N.......... > ff ff ff ff ff ff ff ff 00 53 99 9e ff ff ff ff .........S...... > backtrace: > [<000000004a10c249>] kmalloc_node_trace+0x22/0x60 > [<00000000648f7950>] blk_mq_alloc_and_init_hctx+0x289/0x350 > [<00000000af06de0e>] blk_mq_realloc_hw_ctxs+0x2fe/0x3d0 > [<00000000e00c1872>] blk_mq_init_allocated_queue+0x48c/0x1440 > [<00000000d16b4e68>] __blk_mq_alloc_disk+0xc8/0x1c0 > [<00000000d10c98c3>] 0xffffffffc450d69d > [<00000000b9299f48>] 0xffffffffc4538392 > [<0000000061c39ed6>] do_one_initcall+0xd0/0x4f0 > [<00000000b389383b>] do_init_module+0x1a4/0x680 > [<0000000087cf3542>] load_module+0x6249/0x7110 > [<00000000beba61b8>] __do_sys_finit_module+0x140/0x200 > [<00000000fdcfff51>] do_syscall_64+0x35/0x80 > [<000000003c0f1f71>] entry_SYSCALL_64_after_hwframe+0x46/0xb0 > > That is because q->ma_ops is set to NULL before blk_release_queue is > called. > > blk_mq_init_queue_data > blk_mq_init_allocated_queue > blk_mq_realloc_hw_ctxs > for (i = 0; i < set->nr_hw_queues; i++) { > old_hctx = xa_load(&q->hctx_table, i); > if (!blk_mq_alloc_and_init_hctx(.., i, ..)) [1] > if (!old_hctx) > break; > > xa_for_each_start(&q->hctx_table, j, hctx, j) > blk_mq_exit_hctx(q, set, hctx, j); [2] > > if (!q->nr_hw_queues) [3] > goto err_hctxs; > > err_exit: > q->mq_ops = NULL; [4] > > blk_put_queue > blk_release_queue > if (queue_is_mq(q)) [5] > blk_mq_release(q); > > [1]: blk_mq_alloc_and_init_hctx failed at i != 0. > [2]: The hctxs allocated by [1] are moved to q->unused_hctx_list and > will be cleaned up in blk_mq_release. > [3]: q->nr_hw_queues is 0. > [4]: Set q->mq_ops to NULL. > [5]: queue_is_mq returns false due to [4]. And blk_mq_release > will not be called. The hctxs in q->unused_hctx_list are leaked. > > To fix it, call blk_release_queue in exception path. > > Fixes: 2f8f1336a48b ("blk-mq: always free hctx after request queue is freed") > Signed-off-by: Yuan Can <yuancan@huawei.com> > Signed-off-by: Chen Jun <chenjun102@huawei.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Thanks, Ming
On Mon, 31 Oct 2022 03:12:42 +0000, Chen Jun wrote: > There is a kmemleak caused by modprobe null_blk.ko > > unreferenced object 0xffff8881acb1f000 (size 1024): > comm "modprobe", pid 836, jiffies 4294971190 (age 27.068s) > hex dump (first 32 bytes): > 00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N.......... > ff ff ff ff ff ff ff ff 00 53 99 9e ff ff ff ff .........S...... > backtrace: > [<000000004a10c249>] kmalloc_node_trace+0x22/0x60 > [<00000000648f7950>] blk_mq_alloc_and_init_hctx+0x289/0x350 > [<00000000af06de0e>] blk_mq_realloc_hw_ctxs+0x2fe/0x3d0 > [<00000000e00c1872>] blk_mq_init_allocated_queue+0x48c/0x1440 > [<00000000d16b4e68>] __blk_mq_alloc_disk+0xc8/0x1c0 > [<00000000d10c98c3>] 0xffffffffc450d69d > [<00000000b9299f48>] 0xffffffffc4538392 > [<0000000061c39ed6>] do_one_initcall+0xd0/0x4f0 > [<00000000b389383b>] do_init_module+0x1a4/0x680 > [<0000000087cf3542>] load_module+0x6249/0x7110 > [<00000000beba61b8>] __do_sys_finit_module+0x140/0x200 > [<00000000fdcfff51>] do_syscall_64+0x35/0x80 > [<000000003c0f1f71>] entry_SYSCALL_64_after_hwframe+0x46/0xb0 > > [...] Applied, thanks! [1/1] blk-mq: Fix kmemleak in blk_mq_init_allocated_queue commit: 943f45b9399ed8b2b5190cbc797995edaa97f58f Best regards,
diff --git a/block/blk-mq.c b/block/blk-mq.c index 33292c01875d..308b0ba71dba 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -4188,9 +4188,7 @@ int blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, return 0; err_hctxs: - xa_destroy(&q->hctx_table); - q->nr_hw_queues = 0; - blk_mq_sysfs_deinit(q); + blk_mq_release(q); err_poll: blk_stat_free_callback(q->poll_cb); q->poll_cb = NULL;
There is a kmemleak caused by modprobe null_blk.ko unreferenced object 0xffff8881acb1f000 (size 1024): comm "modprobe", pid 836, jiffies 4294971190 (age 27.068s) hex dump (first 32 bytes): 00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N.......... ff ff ff ff ff ff ff ff 00 53 99 9e ff ff ff ff .........S...... backtrace: [<000000004a10c249>] kmalloc_node_trace+0x22/0x60 [<00000000648f7950>] blk_mq_alloc_and_init_hctx+0x289/0x350 [<00000000af06de0e>] blk_mq_realloc_hw_ctxs+0x2fe/0x3d0 [<00000000e00c1872>] blk_mq_init_allocated_queue+0x48c/0x1440 [<00000000d16b4e68>] __blk_mq_alloc_disk+0xc8/0x1c0 [<00000000d10c98c3>] 0xffffffffc450d69d [<00000000b9299f48>] 0xffffffffc4538392 [<0000000061c39ed6>] do_one_initcall+0xd0/0x4f0 [<00000000b389383b>] do_init_module+0x1a4/0x680 [<0000000087cf3542>] load_module+0x6249/0x7110 [<00000000beba61b8>] __do_sys_finit_module+0x140/0x200 [<00000000fdcfff51>] do_syscall_64+0x35/0x80 [<000000003c0f1f71>] entry_SYSCALL_64_after_hwframe+0x46/0xb0 That is because q->ma_ops is set to NULL before blk_release_queue is called. blk_mq_init_queue_data blk_mq_init_allocated_queue blk_mq_realloc_hw_ctxs for (i = 0; i < set->nr_hw_queues; i++) { old_hctx = xa_load(&q->hctx_table, i); if (!blk_mq_alloc_and_init_hctx(.., i, ..)) [1] if (!old_hctx) break; xa_for_each_start(&q->hctx_table, j, hctx, j) blk_mq_exit_hctx(q, set, hctx, j); [2] if (!q->nr_hw_queues) [3] goto err_hctxs; err_exit: q->mq_ops = NULL; [4] blk_put_queue blk_release_queue if (queue_is_mq(q)) [5] blk_mq_release(q); [1]: blk_mq_alloc_and_init_hctx failed at i != 0. [2]: The hctxs allocated by [1] are moved to q->unused_hctx_list and will be cleaned up in blk_mq_release. [3]: q->nr_hw_queues is 0. [4]: Set q->mq_ops to NULL. [5]: queue_is_mq returns false due to [4]. And blk_mq_release will not be called. The hctxs in q->unused_hctx_list are leaked. To fix it, call blk_release_queue in exception path. Fixes: 2f8f1336a48b ("blk-mq: always free hctx after request queue is freed") Signed-off-by: Yuan Can <yuancan@huawei.com> Signed-off-by: Chen Jun <chenjun102@huawei.com> --- block/blk-mq.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)