cbcvebase.
CVE-2021-46981
published 2024-02-28

CVE-2021-46981: In the Linux kernel, the following vulnerability has been resolved: nbd: Fix NULL pointer in flush_workqueue Open /dev/nbdX first, the config_refs will be 1…

PriorityP420medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.25%
16.4th percentile
In the Linux kernel, the following vulnerability has been resolved: nbd: Fix NULL pointer in flush_workqueue 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 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] n

Affected

23 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 5.10.38-1 (bookworm)linux 5.10.38-1 (bookworm)
linuxlinux
linuxlinux
linuxlinux
linuxlinux
linuxlinux>= 4.14.149 < 4.154.15
linuxlinux>= 4.19.79 < 4.204.20
linuxlinux>= 5.3.6 < 5.45.4
linuxlinux>= e9e006f5fcf2bab59149cb38a48a4817c1b538b4 < 1c4962df938891af9ab4775f5224ef86017641071c4962df938891af9ab4775f5224ef8601764107
linuxlinux>= e9e006f5fcf2bab59149cb38a48a4817c1b538b4 < cde4b55cfb24522dcbba80bbdb0c082303e76c43cde4b55cfb24522dcbba80bbdb0c082303e76c43
linuxlinux>= e9e006f5fcf2bab59149cb38a48a4817c1b538b4 < b31d237796fd618379ec8e0f4de3370b5e4aeee7b31d237796fd618379ec8e0f4de3370b5e4aeee7
linuxlinux>= e9e006f5fcf2bab59149cb38a48a4817c1b538b4 < 54b78ba7e96e5fe1edb8054e375d31a6c0dc60dc54b78ba7e96e5fe1edb8054e375d31a6c0dc60dc
linuxlinux>= e9e006f5fcf2bab59149cb38a48a4817c1b538b4 < 79ebe9110fa458d58f1fceb078e2068d7ad3739079ebe9110fa458d58f1fceb078e2068d7ad37390
linuxlinux_kernel
linuxlinux_kernel>= 0 < 5.10.38-15.10.38-1
linuxlinux_kernel>= 0 < 5.10.38-15.10.38-1
linuxlinux_kernel>= 0 < 5.10.38-15.10.38-1
linuxlinux_kernel>= 0 < 5.10.38-15.10.38-1
linuxlinux_kernel>= 0 < 4.15.0-225.2374.15.0-225.237
linuxlinux_kernel>= 5.11 < 5.11.225.11.22
linuxlinux_kernel>= 5.12 < 5.12.55.12.5
linuxlinux_kernel>= 5.4 < 5.4.1205.4.120
linuxlinux_kernel>= 5.5 < 5.10.385.10.38

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv5.5MEDIUM
vendor_debian5.5MEDIUM
vendor_redhat5.5MEDIUM
vendor_ubuntu5.5MEDIUM
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