projects
/
linux-2.6-microblaze.git
/ commitdiff
commit
grep
author
committer
pickaxe
?
search:
re
summary
|
shortlog
|
log
|
commit
| commitdiff |
tree
raw
|
patch
| inline |
side by side
(parent:
190515f
)
nbd: Fix NULL pointer in flush_workqueue
author
Sun Ke
<sunke32@huawei.com>
Wed, 12 May 2021 11:43:30 +0000
(19:43 +0800)
committer
Jens Axboe
<axboe@kernel.dk>
Wed, 12 May 2021 14:42:43 +0000
(08:42 -0600)
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:
e9e006f5fcf2
("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>
drivers/block/nbd.c
patch
|
blob
|
history
diff --git
a/drivers/block/nbd.c
b/drivers/block/nbd.c
index
4ff71b5
..
974da56
100644
(file)
--- a/
drivers/block/nbd.c
+++ b/
drivers/block/nbd.c
@@
-1980,7
+1980,8
@@
static void nbd_disconnect_and_put(struct nbd_device *nbd)
* config ref and try to destroy the workqueue from inside the work
* queue.
*/
- flush_workqueue(nbd->recv_workq);
+ if (nbd->recv_workq)
+ flush_workqueue(nbd->recv_workq);
if (test_and_clear_bit(NBD_RT_HAS_CONFIG_REF,
&nbd->config->runtime_flags))
nbd_config_put(nbd);