On Mon, May 29, 2023 at 10:16:36PM +0530, Harshit Mogalapalli wrote:
Hi Greg,
On 29/05/23 12:39 am, Greg Kroah-Hartman wrote:
From: Chaitanya Kulkarni kch@nvidia.com
[ Upstream commit 63f8793ee60513a09f110ea460a6ff2c33811cdb ]
Make sure to check device queue mode in the null_validate_conf() and return error for NULL_Q_RQ as we don't allow legacy I/O path, without this patch we get OOPs when queue mode is set to 1 from configfs, following are repro steps :-
modprobe null_blk nr_devices=0 mkdir config/nullb/nullb0 echo 1 > config/nullb/nullb0/memory_backed echo 4096 > config/nullb/nullb0/blocksize echo 20480 > config/nullb/nullb0/size echo 1 > config/nullb/nullb0/queue_mode echo 1 > config/nullb/nullb0/power
Entering kdb (current=0xffff88810acdd080, pid 2372) on processor 42 Oops: (null) due to oops @ 0xffffffffc041c329 CPU: 42 PID: 2372 Comm: sh Tainted: G O N 6.3.0-rc5lblk+ #5 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 RIP: 0010:null_add_dev.part.0+0xd9/0x720 [null_blk] Code: 01 00 00 85 d2 0f 85 a1 03 00 00 48 83 bb 08 01 00 00 00 0f 85 f7 03 00 00 80 bb 62 01 00 00 00 48 8b 75 20 0f 85 6d 02 00 00 <48> 89 6e 60 48 8b 75 20 bf 06 00 00 00 e8 f5 37 2c c1 48 8b 75 20 RSP: 0018:ffffc900052cbde0 EFLAGS: 00010246 RAX: 0000000000000001 RBX: ffff88811084d800 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888100042e00 RBP: ffff8881053d8200 R08: ffffc900052cbd68 R09: ffff888105db2000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000002 R13: ffff888104765200 R14: ffff88810eec1748 R15: ffff88810eec1740 FS: 00007fd445fd1740(0000) GS:ffff8897dfc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000060 CR3: 0000000166a00000 CR4: 0000000000350ee0 DR0: ffffffff8437a488 DR1: ffffffff8437a489 DR2: ffffffff8437a48a DR3: ffffffff8437a48b DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace:
<TASK> nullb_device_power_store+0xd1/0x120 [null_blk] configfs_write_iter+0xb4/0x120 vfs_write+0x2ba/0x3c0 ksys_write+0x5f/0xe0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc RIP: 0033:0x7fd4460c57a7 Code: 0d 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24 RSP: 002b:00007ffd3792a4a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fd4460c57a7 RDX: 0000000000000002 RSI: 000055b43c02e4c0 RDI: 0000000000000001 RBP: 000055b43c02e4c0 R08: 000000000000000a R09: 00007fd44615b4e0 R10: 00007fd44615b3e0 R11: 0000000000000246 R12: 0000000000000002 R13: 00007fd446198520 R14: 0000000000000002 R15: 00007fd446198700 </TASK>
Signed-off-by: Chaitanya Kulkarni kch@nvidia.com Reviewed-by: Damien Le Moal dlemoal@kernel.org Reviewed-by: Ming Lei ming.lei@redhat.com Reviewed-by: Nitesh Shetty nj.shetty@samsung.com Link: https://lore.kernel.org/r/20230416220339.43845-1-kch@nvidia.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org
drivers/block/null_blk.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c index b499e72b2847e..38660b5cfb73c 100644 --- a/drivers/block/null_blk.c +++ b/drivers/block/null_blk.c @@ -1780,6 +1780,11 @@ static int null_init_tag_set(struct nullb *nullb, struct blk_mq_tag_set *set) static void null_validate_conf(struct nullb_device *dev) {
- if (dev->queue_mode == NULL_Q_RQ) {
pr_err("legacy IO path is no longer available\n");return -EINVAL;- }
This patch introduces a warning during build:
drivers/block/null_blk.c: In function 'null_validate_conf': drivers/block/null_blk.c:1785:10: warning: 'return' with a value, in function returning void return -EINVAL; ^ drivers/block/null_blk.c:1781:13: note: declared here static void null_validate_conf(struct nullb_device *dev) ^~~~~~~~~~~~~~~~~~
The commit message explains on how to reproduce the bug, with my CONFIG(CONFIG_BLK_DEV_NULL_BLK enabled) I am unable to reproduce this bug on 4.14.315. So I think we can drop this patch from 4.14.y release as it introduces the above warning.
Commit 5c4bd1f40c23d is not present on 4.14.y, which changes the return type of this.
Given that the bug mentioned in the commit message is not reproducible on 4.14.y, I think we can drop this patch instead of taking a prerequisite(5c4bd1f40c23d).
Note: I don't see this patch being queued up for 5.4.y.
[Thanks to Vegard for helping with this.]
Thanks, I've dropped it now!
greg k-h