Sun Ke b97c15e96b nbd: Fix NULL pointer in flush_workqueue ... commit 79ebe9110f upstream. Open /dev/nbdX first, the config_refs will be 1 and the pointers in nbd_device are still null. Disconnect /dev/nbdX, then reference a null recv_workq. The protection by config_refs in nbd_genl_disconnect is useless. [ 656.366194] BUG: kernel NULL pointer dereference, address: 0000000000000020 [ 656.368943] #PF: supervisor write access in kernel mode [ 656.369844] #PF: error_code(0x0002) - not-present page [ 656.370717] PGD 10cc87067 P4D 10cc87067 PUD 1074b4067 PMD 0 [ 656.371693] Oops: 0002 [#1] SMP [ 656.372242] CPU: 5 PID: 7977 Comm: nbd-client Not tainted 5.11.0-rc5-00040-g76c057c84d28 #1 [ 656.373661] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014 [ 656.375904] RIP: 0010:mutex_lock+0x29/0x60 [ 656.376627] Code: 00 0f 1f 44 00 00 55 48 89 fd 48 83 05 6f d7 fe 08 01 e8 7a c3 ff ff 48 83 05 6a d7 fe 08 01 31 c0 65 48 8b 14 25 00 6d 01 00 <f0> 48 0f b1 55 d [ 656.378934] RSP: 0018:ffffc900005eb9b0 EFLAGS: 00010246 [ 656.379350] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 656.379915] RDX: ffff888104cf2600 RSI: ffffffffaae8f452 RDI: 0000000000000020 [ 656.380473] RBP: 0000000000000020 R08: 0000000000000000 R09: ffff88813bd6b318 [ 656.381039] R10: 00000000000000c7 R11: fefefefefefefeff R12: ffff888102710b40 [ 656.381599] R13: ffffc900005eb9e0 R14: ffffffffb2930680 R15: ffff88810770ef00 [ 656.382166] FS: 00007fdf117ebb40(0000) GS:ffff88813bd40000(0000) knlGS:0000000000000000 [ 656.382806] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 656.383261] CR2: 0000000000000020 CR3: 0000000100c84000 CR4: 00000000000006e0 [ 656.383819] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 656.384370] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 656.384927] Call Trace: [ 656.385111] flush_workqueue+0x92/0x6c0 [ 656.385395] nbd_disconnect_and_put+0x81/0xd0 [ 656.385716] nbd_genl_disconnect+0x125/0x2a0 [ 656.386034] genl_family_rcv_msg_doit.isra.0+0x102/0x1b0 [ 656.386422] genl_rcv_msg+0xfc/0x2b0 [ 656.386685] ? nbd_ioctl+0x490/0x490 [ 656.386954] ? genl_family_rcv_msg_doit.isra.0+0x1b0/0x1b0 [ 656.387354] netlink_rcv_skb+0x62/0x180 [ 656.387638] genl_rcv+0x34/0x60 [ 656.387874] netlink_unicast+0x26d/0x590 [ 656.388162] netlink_sendmsg+0x398/0x6c0 [ 656.388451] ? netlink_rcv_skb+0x180/0x180 [ 656.388750] ____sys_sendmsg+0x1da/0x320 [ 656.389038] ? ____sys_recvmsg+0x130/0x220 [ 656.389334] ___sys_sendmsg+0x8e/0xf0 [ 656.389605] ? ___sys_recvmsg+0xa2/0xf0 [ 656.389889] ? handle_mm_fault+0x1671/0x21d0 [ 656.390201] __sys_sendmsg+0x6d/0xe0 [ 656.390464] __x64_sys_sendmsg+0x23/0x30 [ 656.390751] do_syscall_64+0x45/0x70 [ 656.391017] entry_SYSCALL_64_after_hwframe+0x44/0xa9 To fix it, just add if (nbd->recv_workq) to nbd_disconnect_and_put(). Fixes: e9e006f5fc ("nbd: fix max number of supported devs") Signed-off-by: Sun Ke <sunke32@huawei.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Link: https://lore.kernel.org/r/20210512114331.1233964-2-sunke32@huawei.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Xinghui Li <korantli@tencent.com>		2024-06-11 21:18:44 +08:00
..
aoe	block: aoe: Fix kernel crash due to atomic sleep when exiting	2019-08-08 07:29:02 -06:00
drbd	block: drbd: remove a stray unlock in __drbd_send_protocol()	2019-11-08 06:55:22 -07:00
mtip32xx	block: mtip32xx: Remove call to memset after dma_alloc_coherent	2019-06-29 09:42:50 -06:00
paride	paride/pcd: need to check if cd->disk is null in pcd_detect	2019-09-04 07:04:37 -06:00
rsxx	ock: sync codes to ock 5.4.119-20.0009.21	2024-06-11 20:27:38 +08:00
xen-blkback	ock: sync codes to ock 5.4.119-20.0009.21	2024-06-11 20:27:38 +08:00
zram	ock: sync codes to ock 5.4.119-20.0009.21	2024-06-11 20:27:38 +08:00
Kconfig	ock: sync codes to ock 5.4.119-20.0009.21	2024-06-11 20:27:38 +08:00
Makefile	drivers/block: Remove DAC960 driver	2018-10-17 09:42:30 -06:00
amiflop.c	treewide: Add SPDX license identifier for more missed files	2019-05-21 10:50:45 +02:00
ataflop.c	ataflop: Mark expected switch fall-through	2019-07-29 15:24:58 -06:00
brd.c	tkernel: add base tlinux kernel interfaces	2024-06-11 20:09:33 +08:00
cryptoloop.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 30	2019-05-24 17:27:10 +02:00
floppy.c	ock: sync codes to ock 5.4.119-20.0009.21	2024-06-11 20:27:38 +08:00
loop.c	ock: sync codes to ock 5.4.119-20.0009.21	2024-06-11 20:27:38 +08:00
loop.h	block/loop: Use global lock for ioctl() operation.	2018-11-08 06:30:11 -07:00
nbd.c	nbd: Fix NULL pointer in flush_workqueue	2024-06-11 21:18:44 +08:00
null_blk.h	null_blk: format pr_* logs with pr_fmt	2019-09-16 08:38:29 -06:00
null_blk_main.c	ock: sync codes to ock 5.4.119-20.0009.21	2024-06-11 20:27:38 +08:00
null_blk_zoned.c	ock: sync codes to ock 5.4.119-20.0009.21	2024-06-11 20:27:38 +08:00
pktcdvd.c	pktcdvd: remove warning on attempting to register non-passthrough dev	2019-09-22 10:01:05 -06:00
ps3disk.c	ock: sync codes to ock 5.4.119-20.0009.21	2024-06-11 20:27:38 +08:00
ps3vram.c	block/ps3vram: Use %llu to format sector_t after LBDAF removal	2019-06-13 03:17:50 -06:00
rbd.c	ock: sync codes to ock 5.4.119-20.0009.21	2024-06-11 20:27:38 +08:00
rbd_types.h	rbd: support for object-map and fast-diff	2019-07-08 14:01:45 +02:00
skd_main.c	Linux 5.2-rc6	2019-07-01 08:16:08 -06:00
skd_s1120.h	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 497	2019-06-19 17:09:53 +02:00
sunvdc.c	treewide: Add SPDX license identifier for more missed files	2019-05-21 10:50:45 +02:00
swim.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152	2019-05-30 11:26:32 -07:00
swim3.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152	2019-05-30 11:26:32 -07:00
swim_asm.S	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152	2019-05-30 11:26:32 -07:00
sx8.c	sx8: use a per-host tag_set	2018-11-09 08:14:14 -07:00
umem.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 349	2019-06-05 17:37:08 +02:00
umem.h	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 348	2019-06-05 17:37:08 +02:00
virtio_blk.c	ock: sync codes to ock 5.4.119-20.0009.21	2024-06-11 20:27:38 +08:00
xen-blkfront.c	ock: sync codes to ock 5.4.119-20.0009.21	2024-06-11 20:27:38 +08:00
xsysace.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500	2019-06-19 17:09:55 +02:00
z2ram.c	powerpc updates for 4.20	2018-10-26 14:36:21 -07:00