Linux: Use After Free
CVE-2023-53194 is a high-severity use after free vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 85afd3007465f8bc74afffbf5b84ec29f5310b03, 0d04e45c65f0785e558b93d2631d58680f263e10, eb5b59931d20f3b02076fae49e85282310b12012 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.17% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 85afd3007465f8bc74afffbf5b84ec29f5310b03 or 0d04e45c65f0785e558b93d2631d58680f263e10 or eb5b59931d20f3b02076fae49e85282310b12012 or 08e8cf5f2d9ec383a2e339a2711b62a54ff3fba0, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.15.113 or 6.1.81 or 6.3.4, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 4534a70b7056fd4b9a1c6db5a4ce3c98546b291e up to, but not including, 85afd3007465f8bc74afffbf5b84ec29f5310b03; 4534a70b7056fd4b9a1c6db5a4ce3c98546b291e up to, but not including, 0d04e45c65f0785e558b93d2631d58680f263e10; 4534a70b7056fd4b9a1c6db5a4ce3c98546b291e up to, but not including, eb5b59931d20f3b02076fae49e85282310b12012; 4534a70b7056fd4b9a1c6db5a4ce3c98546b291e up to, but not including, 08e8cf5f2d9ec383a2e339a2711b62a54ff3fba0; 5.15 | 85afd3007465f8bc74afffbf5b84ec29f5310b03, 0d04e45c65f0785e558b93d2631d58680f263e10, eb5b59931d20f3b02076fae49e85282310b12012, 08e8cf5f2d9ec383a2e339a2711b62a54ff3fba0 |
| Linux | Linux Kernel | 5.15 up to, but not including, 5.15.113; 5.16 up to, but not including, 6.1.81; 6.2 up to, but not including, 6.3.4 | 5.15.113, 6.1.81, 6.3.4 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.4 | High | CNA |
| CVSS 3.1 | 7.8 | High | NVD |
Official description
In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: Add length check in indx_get_root This adds a length check to guarantee the retrieved index root is legit. [ 162.459513] BUG: KASAN: use-after-free in hdr_find_e.isra.0+0x10c/0x320 [ 162.460176] Read of size 2 at addr ffff8880037bca99 by task mount/243 [ 162.460851] [ 162.461252] CPU: 0 PID: 243 Comm: mount Not tainted 6.0.0-rc7 #42 [ 162.461744] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 162.462609] Call Trace: [ 162.462954] <TASK> [ 162.463276] dump_stack_lvl+0x49/0x63 [ 162.463822] print_report.cold+0xf5/0x689 [ 162.464608] ? unwind_get_return_address+0x3a/0x60 [ 162.465766] ? hdr_find_e.isra.0+0x10c/0x320 [ 162.466975] kasan_report+0xa7/0x130 [ 162.467506] ? _raw_spin_lock_irq+0xc0/0xf0 [ 162.467998] ? hdr_find_e.isra.0+0x10c/0x320 [ 162.468536] __asan_load2+0x68/0x90 [ 162.468923] hdr_find_e.isra.0+0x10c/0x320 [ 162.469282] ? cmp_uints+0xe0/0xe0 [ 162.469557] ? cmp_sdh+0x90/0x90 [ 162.469864] ? ni_find_attr+0x214/0x300 [ 162.470217] ? ni_load_mi+0x80/0x80 [ 162.470479] ? entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 162.470931] ? ntfs_bread_run+0x190/0x190 [ 162.471307] ? indx_get_root+0xe4/0x190 [ 162.471556] ? indx_get_root+0x140/0x190 [ 162.471833] ? indx_init+0x1e0/0x1e0 [ 162.472069] ? fnd_clear+0x115/0x140 [ 162.472363] ? _raw_spin_lock_irqsave+0x100/0x100 [ 162.472731] indx_find+0x184/0x470 [ 162.473461] ? sysvec_apic_timer_interrupt+0x57/0xc0 [ 162.474429] ? indx_find_buffer+0x2d0/0x2d0 [ 162.474704] ? do_syscall_64+0x3b/0x90 [ 162.474962] dir_search_u+0x196/0x2f0 [ 162.475381] ? ntfs_nls_to_utf16+0x450/0x450 [ 162.475661] ? ntfs_security_init+0x3d6/0x440 [ 162.475906] ? is_sd_valid+0x180/0x180 [ 162.476191] ntfs_extend_init+0x13f/0x2c0 [ 162.476496] ? ntfs_fix_post_read+0x130/0x130 [ 162.476861] ? iput.part.0+0x286/0x320 [ 162.477325] ntfs_fill_super+0x11e0/0x1b50 [ 162.477709] ? put_ntfs+0x1d0/0x1d0 [ 162.477970] ? vsprintf+0x20/0x20 [ 162.478258] ? set_blocksize+0x95/0x150 [ 162.478538] get_tree_bdev+0x232/0x370 [ 162.478789] ? put_ntfs+0x1d0/0x1d0 [ 162.479038] ntfs_fs_get_tree+0x15/0x20 [ 162.479374] vfs_get_tree+0x4c/0x130 [ 162.479729] path_mount+0x654/0xfe0 [ 162.480124] ? putname+0x80/0xa0 [ 162.480484] ? finish_automount+0x2e0/0x2e0 [ 162.480894] ? putname+0x80/0xa0 [ 162.481467] ? kmem_cache_free+0x1c4/0x440 [ 162.482280] ? putname+0x80/0xa0 [ 162.482714] do_mount+0xd6/0xf0 [ 162.483264] ? path_mount+0xfe0/0xfe0 [ 162.484782] ? __kasan_check_write+0x14/0x20 [ 162.485593] __x64_sys_mount+0xca/0x110 [ 162.486024] do_syscall_64+0x3b/0x90 [ 162.486543] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 162.487141] RIP: 0033:0x7f9d374e948a [ 162.488324] Code: 48 8b 0d 11 fa 2a 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5 00 00 008 [ 162.489728] RSP: 002b:00007ffe30e73d18 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 [ 162.490971] RAX: ffffffffffffffda RBX: 0000561cdb43a060 RCX: 00007f9d374e948a [ 162.491669] RDX: 0000561cdb43a260 RSI: 0000561cdb43a2e0 RDI: 0000561cdb442af0 [ 162.492050] RBP: 0000000000000000 R08: 0000561cdb43a280 R09: 0000000000000020 [ 162.492459] R10: 00000000c0ed0000 R11: 0000000000000206 R12: 0000561cdb442af0 [ 162.493183] R13: 0000561cdb43a260 R14: 0000000000000000 R15: 00000000ffffffff [ 162.493644] </TASK> [ 162.493908] [ 162.494214] The buggy address belongs to the physical page: [ 162.494761] page:000000003e38a3d5 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x37bc [ 162.496064] flags: 0xfffffc0000000(node=0|zone=1|lastcpupid=0x1fffff) [ 162.497278] raw: 000fffffc0000000 ffffea00000df1c8 ffffea00000df008 0000000000000000 [ 162.498928] raw: 0000000000000000 0000000000240000 00000000ffffffff 0000000000000000 [ 162.500542] page dumped becau ---truncated---
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use After Free
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Use After Free vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
Spotted an error? Tell us.