hfsplus: don't query the device logical block size multiple times
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 1 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-787 and the CVSS impact.
Summary
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---
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 3.0.8 to before 3.1 | 3.1 | Patch available | CNA |
| Linux | Linux | 3.1 and later | 4.19.325, 5.4.287, 5.10.231, 5.15.174, 6.1.120, 6.6.64, 6.11.11, 6.12.2, 6.13 | Patch available | CNA |
- Linux VendorLinux Affected 3.0.8 to before 3.1 Fixed in 3.1 Patch available CNA
- Linux VendorLinux Affected 3.1 and later Fixed in 4.19.325, 5.4.287, 5.10.231, 5.15.174, 6.1.120, 6.6.64, 6.11.11, 6.12.2, 6.13 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 3.0.8 to before 4.19.325; 4.20 to before 5.4.287; 5.5 to before 5.10.231; 5.11 to before 5.15.174; 5.16 to before 6.1.120; 6.2 to before 6.6.64; 6.7 to before 6.11.11; 6.12 to before 6.12.2 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 3.0.8 to before 4.19.325; 4.20 to before 5.4.287; 5.5 to before 5.10.231; 5.11 to before 5.15.174; 5.16 to before 6.1.120; 6.2 to before 6.6.64; 6.7 to before 6.11.11; 6.12 to before 6.12.2 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 3.1
- Fix · CNA Linux (Linux) Fixed in 4.19.325, 5.4.287, 5.10.231, 5.15.174, 6.1.120, 6.6.64, 6.11.11, 6.12.2, 6.13
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
Not affected: 3 products
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2024-56548
- 2026-10-03 Alias added: GHSA-64p7-wm49-vgg4
References
Patch 9
- https://git.kernel.org/stable/c/baccb5e12577b7a9eff54ffba301fdaa0f3ee5a8
- https://git.kernel.org/stable/c/f57725bcc5816425e25218fdf5fb6923bc578cdf
- https://git.kernel.org/stable/c/e8a2b1c1c2ea85e9a5a2d0c5a5a7e7c639feb866
- https://git.kernel.org/stable/c/06cbfbb13ac88f4154c2eb4bc4176f9d10139847
- https://git.kernel.org/stable/c/3d7bda75e1a6239db053c73acde17ca146317824
- https://git.kernel.org/stable/c/21900e8478126ff6afe3b66679f676e74d1f8830
- https://git.kernel.org/stable/c/2667c9b7b76efcbc7adbfea249892f20c313b0da
- https://git.kernel.org/stable/c/bfeecda050aa9376f642d5b2a71c4112cc6c8216
- https://git.kernel.org/stable/c/1c82587cb57687de3f18ab4b98a8850c789bedcf
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- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2024-56548 · CVE Program
- CVE-2024-56548 · NVD
- FIRST EPSS
- GHSA-64p7-wm49-vgg4 · GitHub Advisory Database · CC BY 4.0
- CVE-2024-56548 · Red Hat security data · CC BY 4.0
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