7.8

CVE-2024-56548: linux Out-of-bounds Write

CVSS: 7.8v3.1HighModified
AliasesUBUNTU-CVE-2024-56548DEBIAN-CVE-2024-56548
Published 27-12-2024Last modified 05-08-2026

Vulnerability summary

CVE-2024-56548 is a high (CVSS 7.8) Out-of-bounds Write vulnerability in linux. EPSS estimates a 0.25% chance of exploitation in the next 30 days, higher than 14.9% of scored vulnerabilities.

Overall risk
31/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.8/10
010
High · v3.1 (CVE.org)
EPSS score
0.25%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 69 · Related 76

Timeline

  1. 27-12-2024
    PublishedVulnerability first disclosed.
  2. 05-08-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: hfsplus: don't query the device logical block size multiple times Devices block sizes may change. One of these cases is a loop device by using ioctl LOOP_SET_BLOCK_SIZE. While this may cause other issues like IO being rejected, in the case of hfsplus, it will allocate a block by using that size and potentially write out-of-bounds when hfsplus_read_wrapper calls hfsplus_submit_bio and the latter function reads a different io_size. Using a new min_io_size initally set to sb_min_blocksize works for the purposes of the original fix, since it will be set to the max between HFSPLUS_SECTOR_SIZE and the first seen logical block size. We still use the max between HFSPLUS_SECTOR_SIZE and min_io_size in case the latter is not initialized. Tested by mounting an hfsplus filesystem with loop block sizes 512, 1024 and 4096. The produced KASAN report before the fix looks like this: [ 419.944641] ================================================================== [ 419.945655] BUG: KASAN: slab-use-after-free in hfsplus_read_wrapper+0x659/0xa0a [ 419.946703] Read of size 2 at addr ffff88800721fc00 by task repro/10678 [ 419.947612] [ 419.947846] CPU: 0 UID: 0 PID: 10678 Comm: repro Not tainted 6.12.0-rc5-00008-gdf56e0f2f3ca #84 [ 419.949007] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014 [ 419.950035] Call Trace: [ 419.950384] <TASK> [ 419.950676] dump_stack_lvl+0x57/0x78 [ 419.951212] ? hfsplus_read_wrapper+0x659/0xa0a [ 419.951830] print_report+0x14c/0x49e [ 419.952361] ? __virt_addr_valid+0x267/0x278 [ 419.952979] ? kmem_cache_debug_flags+0xc/0x1d [ 419.953561] ? hfsplus_read_wrapper+0x659/0xa0a [ 419.954231] kasan_report+0x89/0xb0 [ 419.954748] ? hfsplus_read_wrapper+0x659/0xa0a [ 419.955367] hfsplus_read_wrapper+0x659/0xa0a [ 419.955948] ? __pfx_hfsplus_read_wrapper+0x10/0x10 [ 419.956618] ? do_raw_spin_unlock+0x59/0x1a9 [ 419.957214] ? _raw_spin_unlock+0x1a/0x2e [ 419.957772] hfsplus_fill_super+0x348/0x1590 [ 419.958355] ? hlock_class+0x4c/0x109 [ 419.958867] ? __pfx_hfsplus_fill_super+0x10/0x10 [ 419.959499] ? __pfx_string+0x10/0x10 [ 419.960006] ? lock_acquire+0x3e2/0x454 [ 419.960532] ? bdev_name.constprop.0+0xce/0x243 [ 419.961129] ? __pfx_bdev_name.constprop.0+0x10/0x10 [ 419.961799] ? pointer+0x3f0/0x62f [ 419.962277] ? __pfx_pointer+0x10/0x10 [ 419.962761] ? vsnprintf+0x6c4/0xfba [ 419.963178] ? __pfx_vsnprintf+0x10/0x10 [ 419.963621] ? setup_bdev_super+0x376/0x3b3 [ 419.964029] ? snprintf+0x9d/0xd2 [ 419.964344] ? __pfx_snprintf+0x10/0x10 [ 419.964675] ? lock_acquired+0x45c/0x5e9 [ 419.965016] ? set_blocksize+0x139/0x1c1 [ 419.965381] ? sb_set_blocksize+0x6d/0xae [ 419.965742] ? __pfx_hfsplus_fill_super+0x10/0x10 [ 419.966179] mount_bdev+0x12f/0x1bf [ 419.966512] ? __pfx_mount_bdev+0x10/0x10 [ 419.966886] ? vfs_parse_fs_string+0xce/0x111 [ 419.967293] ? __pfx_vfs_parse_fs_string+0x10/0x10 [ 419.967702] ? __pfx_hfsplus_mount+0x10/0x10 [ 419.968073] legacy_get_tree+0x104/0x178 [ 419.968414] vfs_get_tree+0x86/0x296 [ 419.968751] path_mount+0xba3/0xd0b [ 419.969157] ? __pfx_path_mount+0x10/0x10 [ 419.969594] ? kmem_cache_free+0x1e2/0x260 [ 419.970311] do_mount+0x99/0xe0 [ 419.970630] ? __pfx_do_mount+0x10/0x10 [ 419.971008] __do_sys_mount+0x199/0x1c9 [ 419.971397] do_syscall_64+0xd0/0x135 [ 419.971761] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 419.972233] RIP: 0033:0x7c3cb812972e [ 419.972564] Code: 48 8b 0d f5 46 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d c2 46 0d 00 f7 d8 64 89 01 48 [ 419.974371] RSP: 002b:00007ffe30632548 EFLAGS: 00000286 ORIG_RAX: 00000000000000a5 [ 419.975048] RAX: ffffffffffffffda RBX: 00007ffe306328d8 RCX: 00007c3cb812972e [ 419.975701] RDX: 0000000020000000 RSI: 0000000020000c80 RDI: ---truncated---

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.25%

Chance of exploitation in the next 30 days

Percentile

15%

Versus all other CVEs

30-day change

0.00 pp

From 0.24% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.25%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Ubuntu134 products
  • linuxAll versions (No fix recorded) | < 4.4.0-278.312 | < 4.15.0-247.259 | < 5.4.0-211.231 | < 5.15.0-135.146 | < 6.8.0-58.60
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 4.4.0-1152.158 | < 4.4.0-1190.205 | < 4.15.0-1189.202 | < 5.4.0-1142.152 | < 5.15.0-1080.87 | < 6.8.0-1027.29
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 6596528e391ad978a6a120142cba97a1d7324cb6, < baccb5e12577b7a9eff54ffba301fdaa0f3ee5a8 | ≥ 6596528e391ad978a6a120142cba97a1d7324cb6, < f57725bcc5816425e25218fdf5fb6923bc578cdf | ≥ 6596528e391ad978a6a120142cba97a1d7324cb6, < e8a2b1c1c2ea85e9a5a2d0c5a5a7e7c639feb866 | ≥ 6596528e391ad978a6a120142cba97a1d7324cb6, < 06cbfbb13ac88f4154c2eb4bc4176f9d10139847 | ≥ 6596528e391ad978a6a120142cba97a1d7324cb6, < 3d7bda75e1a6239db053c73acde17ca146317824 | ≥ 6596528e391ad978a6a120142cba97a1d7324cb6, < 21900e8478126ff6afe3b66679f676e74d1f8830 | ≥ 6596528e391ad978a6a120142cba97a1d7324cb6, < 2667c9b7b76efcbc7adbfea249892f20c313b0da | ≥ 6596528e391ad978a6a120142cba97a1d7324cb6, < bfeecda050aa9376f642d5b2a71c4112cc6c8216 | ≥ 6596528e391ad978a6a120142cba97a1d7324cb6, < 1c82587cb57687de3f18ab4b98a8850c789bedcf | c53c89aba3ebdfc3e9acdb18bb5ee9d2f8a328d0 | ≥ 3.0.8, < 3.1 | 3.1
  • linux_kernel≥ 3.0.8, < 4.19.325 | ≥ 4.20, < 5.4.287 | ≥ 5.5, < 5.10.231 | ≥ 5.11, < 5.15.174 | ≥ 5.16, < 6.1.120 | ≥ 6.2, < 6.6.64 | ≥ 6.7, < 6.11.11 | ≥ 6.12, < 6.12.2
Debian1 product
  • linux< 6.1.123-1 | < 6.12.3-1

3 vendors · 137 products

References

57 links
Show all 57 references