CVE-2023-53198

published 2025-09-15

CVE-2023-53198: In the Linux kernel, the following vulnerability has been resolved: raw: Fix NULL deref in raw_get_next(). Dae R. Jeong reported a NULL deref in raw_get_next()…

Priority P4 20 medium 5.5 CVSS 3.1

AV L AC L PR L UI N S U C N I N A H

In the Linux kernel, the following vulnerability has been resolved:

raw: Fix NULL deref in raw_get_next().

Dae R. Jeong reported a NULL deref in raw_get_next() [0].

It seems that the repro was running these sequences in parallel so
that one thread was iterating on a socket that was being freed in
another netns.

unshare(0x40060200)
r0 = syz_open_procfs(0x0, &(0x7f0000002080)='net/raw\x00')
socket$inet_icmp_raw(0x2, 0x3, 0x1)
pread64(r0, &(0x7f0000000000)=""/10, 0xa, 0x10000000007f)

After commit 0daf07e52709 ("raw: convert raw sockets to RCU"), we
use RCU and hlist_nulls_for_each_entry() to iterate over SOCK_RAW
sockets. However, we should use spinlock for slow paths to avoid
the NULL deref.

Also, SOCK_RAW does not use SLAB_TYPESAFE_BY_RCU, and the slab object
is not reused during iteration in the grace period. In fact, the
lockless readers do not check the nulls marker with get_nulls_value().
So, SOCK_RAW should use hlist instead of hlist_nulls.

Instead of adding an unnecessary barrier by sk_nulls_for_each_rcu(),
let's convert hlist_nulls to hlist and use sk_for_each_rcu() for
fast paths and sk_for_each() and spinlock for /proc/net/raw.

[0]:
general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]
CPU: 2 PID: 20952 Comm: syz-executor.0 Not tainted 6.2.0-g048ec869bafd-dirty #7
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
RIP: 0010:read_pnet include/net/net_namespace.h:383 [inline]
RIP: 0010:sock_net include/net/sock.h:649 [inline]
RIP: 0010:raw_get_next net/ipv4/raw.c:974 [inline]
RIP: 0010:raw_get_idx net/ipv4/raw.c:986 [inline]
RIP: 0010:raw_seq_start+0x431/0x800 net/ipv4/raw.c:995
Code: ef e8 33 3d 94 f7 49 8b 6d 00 4c 89 ef e8 b7 65 5f f7 49 89 ed 49 83 c5 98 0f 84 9a 00 00 00 48 83 c5 c8 48 89 e8 48 c1 e8 03 80 3c 30 00 74 08 48 89 ef e8 00 3d 94 f7 4c 8b 7d 00 48

Affected

16 ranges

Vendor	Product	Version range	Fixed in
debian	linux	< linux 6.1.25-1 (bookworm)	linux 6.1.25-1 (bookworm)
linux	linux	—	—
linux	linux	—	—
linux	linux	—	—
linux	linux	>= 0daf07e527095e64ee8927ce297ab626643e9f51 < b34056bedf04d08ef24f713a7f93bad1274a838d	b34056bedf04d08ef24f713a7f93bad1274a838d
linux	linux	>= 0daf07e527095e64ee8927ce297ab626643e9f51 < 67daeaecd70ef20ab540c21739d3f633734967a1	67daeaecd70ef20ab540c21739d3f633734967a1
linux	linux	>= 0daf07e527095e64ee8927ce297ab626643e9f51 < 0a78cf7264d29abeca098eae0b188a10aabc8a32	0a78cf7264d29abeca098eae0b188a10aabc8a32
linux	linux	>= 5.18.18 < 5.19	5.19
linux	linux	>= 5.19.2 < 5.20	5.20
linux	linux_kernel	—	—
linux	linux_kernel	>= 0 < 6.1.25-1	6.1.25-1
linux	linux_kernel	>= 0 < 6.1.25-1	6.1.25-1
linux	linux_kernel	>= 0 < 6.1.25-1	6.1.25-1
linux	linux_kernel	>= 5.18.18 < 5.19	5.19
linux	linux_kernel	>= 5.19.2 < 6.1.24	6.1.24
linux	linux_kernel	>= 6.2 < 6.2.11	6.2.11

CVSS provenance

nvd v3.1 5.5 MEDIUM CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

osv 5.5 MEDIUM

vendor_debian 5.5 MEDIUM

vendor_redhat 5.5 MEDIUM

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