dm cache: fix out-of-bounds access to the dirty bitset when resizing
dm-cache checks the dirty bits of the cache blocks to be dropped when
shrinking the fast device, but an index bug in bitset iteration causes
out-of-bounds access.
Reproduce steps:
1. create a cache device of 1024 cache blocks (128 bytes dirty bitset)
dmsetup create cmeta --table "0 8192 linear /dev/sdc 0"
dmsetup create cdata --table "0 131072 linear /dev/sdc 8192"
dmsetup create corig --table "0 524288 linear /dev/sdc 262144"
dd if=/dev/zero of=/dev/mapper/cmeta bs=4k count=1 oflag=direct
dmsetup create cache --table "0 524288 cache /dev/mapper/cmeta \
/dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0"
2. shrink the fast device to 512 cache blocks, triggering out-of-bounds
access to the dirty bitset (offset 0x80)
dmsetup suspend cache
dmsetup reload cdata --table "0 65536 linear /dev/sdc 8192"
dmsetup resume cdata
dmsetup resume cache
KASAN reports:
BUG: KASAN: vmalloc-out-of-bounds in cache_preresume+0x269/0x7b0
Read of size 8 at addr ffffc900000f3080 by task dmsetup/131
(...snip...)
The buggy address belongs to the virtual mapping at
[ffffc900000f3000, ffffc900000f5000) created by:
cache_ctr+0x176a/0x35f0
(...snip...)
Memory state around the buggy address:
ffffc900000f2f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
ffffc900000f3000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc900000f3080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
^
ffffc900000f3100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
ffffc900000f3180: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
Fix by making the index post-incremented.
Metrics
Affected Vendors & Products
| Source | ID | Title |
|---|---|---|
Debian DLA |
DLA-4008-1 | linux-6.1 security update |
Debian DLA |
DLA-4075-1 | linux security update |
Debian DSA |
DSA-5818-1 | linux security update |
Ubuntu USN |
USN-7276-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7277-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7288-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7288-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7289-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7289-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7289-3 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7289-4 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7291-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7293-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7294-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7294-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7294-3 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7294-4 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7295-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7305-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7308-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7310-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7331-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7388-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7389-1 | Linux kernel (NVIDIA Tegra) vulnerabilities |
Ubuntu USN |
USN-7390-1 | Linux kernel (Xilinx ZynqMP) vulnerabilities |
Ubuntu USN |
USN-7393-1 | Linux kernel (FIPS) vulnerabilities |
Ubuntu USN |
USN-7401-1 | Linux kernel (AWS) vulnerabilities |
Ubuntu USN |
USN-7413-1 | Linux kernel (IoT) vulnerabilities |
Ubuntu USN |
USN-7449-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7449-2 | Linux kernel (HWE) vulnerabilities |
Ubuntu USN |
USN-7450-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7451-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7452-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7453-1 | Linux kernel (Real-time) vulnerabilities |
Ubuntu USN |
USN-7458-1 | Linux kernel (IBM) vulnerabilities |
Ubuntu USN |
USN-7468-1 | Linux kernel (Azure, N-Series) vulnerabilities |
Ubuntu USN |
USN-7523-1 | Linux kernel (Raspberry Pi Real-time) vulnerabilities |
Ubuntu USN |
USN-7524-1 | Linux kernel (Raspberry Pi) vulnerabilities |
Ubuntu USN |
USN-7539-1 | Linux kernel (Raspberry Pi) vulnerabilities |
Ubuntu USN |
USN-7540-1 | Linux kernel (Raspberry Pi) vulnerabilities |
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
Mon, 03 Nov 2025 23:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Mon, 03 Nov 2025 21:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Wed, 01 Oct 2025 21:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Thu, 19 Dec 2024 02:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
threat_severity
|
threat_severity
|
Wed, 27 Nov 2024 16:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Linux
Linux linux Kernel |
|
| Weaknesses | CWE-125 | |
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.12:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.12:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.12:rc3:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.12:rc4:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.12:rc5:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.12:rc6:*:*:*:*:*:* |
|
| Vendors & Products |
Linux
Linux linux Kernel |
|
| Metrics |
cvssV3_1
|
cvssV3_1
|
Fri, 22 Nov 2024 14:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Tue, 19 Nov 2024 01:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: dm cache: fix out-of-bounds access to the dirty bitset when resizing dm-cache checks the dirty bits of the cache blocks to be dropped when shrinking the fast device, but an index bug in bitset iteration causes out-of-bounds access. Reproduce steps: 1. create a cache device of 1024 cache blocks (128 bytes dirty bitset) dmsetup create cmeta --table "0 8192 linear /dev/sdc 0" dmsetup create cdata --table "0 131072 linear /dev/sdc 8192" dmsetup create corig --table "0 524288 linear /dev/sdc 262144" dd if=/dev/zero of=/dev/mapper/cmeta bs=4k count=1 oflag=direct dmsetup create cache --table "0 524288 cache /dev/mapper/cmeta \ /dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0" 2. shrink the fast device to 512 cache blocks, triggering out-of-bounds access to the dirty bitset (offset 0x80) dmsetup suspend cache dmsetup reload cdata --table "0 65536 linear /dev/sdc 8192" dmsetup resume cdata dmsetup resume cache KASAN reports: BUG: KASAN: vmalloc-out-of-bounds in cache_preresume+0x269/0x7b0 Read of size 8 at addr ffffc900000f3080 by task dmsetup/131 (...snip...) The buggy address belongs to the virtual mapping at [ffffc900000f3000, ffffc900000f5000) created by: cache_ctr+0x176a/0x35f0 (...snip...) Memory state around the buggy address: ffffc900000f2f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffffc900000f3000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffffc900000f3080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ^ ffffc900000f3100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffffc900000f3180: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 Fix by making the index post-incremented. | |
| Title | dm cache: fix out-of-bounds access to the dirty bitset when resizing | |
| References |
|
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-11-03T22:27:58.416Z
Reserved: 2024-10-21T19:36:19.983Z
Link: CVE-2024-50279
Updated: 2025-10-01T15:26:39.292Z
Status : Modified
Published: 2024-11-19T02:16:30.210
Modified: 2025-11-03T23:17:10.030
Link: CVE-2024-50279
OpenCVE Enrichment
No data.
Debian DLA
Debian DSA
Ubuntu USN