cbcvebase.
CVE-2023-53667
published 2025-10-07

CVE-2023-53667: In the Linux kernel, the following vulnerability has been resolved: net: cdc_ncm: Deal with too low values of dwNtbOutMaxSize Currently in…

PriorityP422medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.14%
3.5th percentile
In the Linux kernel, the following vulnerability has been resolved: net: cdc_ncm: Deal with too low values of dwNtbOutMaxSize Currently in cdc_ncm_check_tx_max(), if dwNtbOutMaxSize is lower than the calculated "min" value, but greater than zero, the logic sets tx_max to dwNtbOutMaxSize. This is then used to allocate a new SKB in cdc_ncm_fill_tx_frame() where all the data is handled. For small values of dwNtbOutMaxSize the memory allocated during alloc_skb(dwNtbOutMaxSize, GFP_ATOMIC) will have the same size, due to how size is aligned at alloc time: size = SKB_DATA_ALIGN(size); size += SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); Thus we hit the same bug that we tried to squash with commit 2be6d4d16a084 ("net: cdc_ncm: Allow for dwNtbOutMaxSize to be unset or zero") Low values of dwNtbOutMaxSize do not cause an issue presently because at alloc_skb() time more memory (512b) is allocated than required for the SKB headers alone (320b), leaving some space (512b - 320b = 192b) for CDC data (172b). However, if more elements (for example 3 x u64 = [24b]) were added to one of the SKB header structs, say 'struct skb_shared_info', increasing its original size (320b [320b aligned]) to something larger (344b [384b aligned]), then suddenly the CDC data (172b) no longer fits in the spare SKB data area (512b - 384b = 128b). Consequently the SKB bounds checking semantics fails and panics: skbuff: skb_over_panic: text:ffffffff831f755b len:184 put:172 head:ffff88811f1c6c00 data:ffff88811f1c6c00 tail:0xb8 end:0x80 dev: ------------[ cut here ]------------ kernel BUG at net/core/skbuff.c:113! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 57 Comm: kworker/0:2 Not tainted 5.15.106-syzkaller-00249-g19c0ed55a470 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Workqueue: mld mld_ifc_work RIP: 0010:skb_panic net/core/skbuff.c:113 [inline] RIP: 0010:skb_over_panic+0x14c/0x150 net/core/skbuff.c:118 [snip] Call Trace: skb_put+0x

Affected

22 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.1.37-1 (bookworm)linux 6.1.37-1 (bookworm)
linuxlinux
linuxlinux>= 289507d3364f96f4b8814726917d572f71350d87 < 2334ff0b343ba6ba7a6c0586fcc83992bbbc17762334ff0b343ba6ba7a6c0586fcc83992bbbc1776
linuxlinux>= 289507d3364f96f4b8814726917d572f71350d87 < bf415bfe7573596ac213b4fd1da9e62cfc9a9413bf415bfe7573596ac213b4fd1da9e62cfc9a9413
linuxlinux>= 289507d3364f96f4b8814726917d572f71350d87 < ff484163dfb61b58f23e4dbd007de1094427669cff484163dfb61b58f23e4dbd007de1094427669c
linuxlinux>= 289507d3364f96f4b8814726917d572f71350d87 < 42b78c8cc774b47023d6d16d96d54cc7015e4a0742b78c8cc774b47023d6d16d96d54cc7015e4a07
linuxlinux>= 289507d3364f96f4b8814726917d572f71350d87 < 9be921854e983a81a0aeeae5febcd87093086e469be921854e983a81a0aeeae5febcd87093086e46
linuxlinux>= 289507d3364f96f4b8814726917d572f71350d87 < 6147745d43ff4e0d2c542e5b93e398ef0ee4db006147745d43ff4e0d2c542e5b93e398ef0ee4db00
linuxlinux>= 289507d3364f96f4b8814726917d572f71350d87 < 72d0240b0ee4794efc683975c213e4b384fea73372d0240b0ee4794efc683975c213e4b384fea733
linuxlinux>= 289507d3364f96f4b8814726917d572f71350d87 < 7e01c7f7046efc2c7c192c3619db43292b98e9977e01c7f7046efc2c7c192c3619db43292b98e997
linuxlinux_kernel
linuxlinux_kernel>= 0 < 5.10.191-15.10.191-1
linuxlinux_kernel>= 0 < 6.1.37-16.1.37-1
linuxlinux_kernel>= 0 < 6.3.7-16.3.7-1
linuxlinux_kernel>= 0 < 6.3.7-16.3.7-1
linuxlinux_kernel>= 3.16 < 4.14.3174.14.317
linuxlinux_kernel>= 4.15 < 4.19.2854.19.285
linuxlinux_kernel>= 4.20 < 5.4.2455.4.245
linuxlinux_kernel>= 5.11 < 5.15.1145.15.114
linuxlinux_kernel>= 5.16 < 6.1.316.1.31
linuxlinux_kernel>= 5.5 < 5.10.1815.10.181
linuxlinux_kernel>= 6.2 < 6.3.56.3.5

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
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