GHSA-X84X-5W8G-XR7G
Vulnerability from github – Published: 2026-01-13 18:31 – Updated: 2026-01-19 15:30In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to avoid updating zero-sized extent in extent cache
As syzbot reported:
F2FS-fs (loop0): __update_extent_tree_range: extent len is zero, type: 0, extent [0, 0, 0], age [0, 0] ------------[ cut here ]------------ kernel BUG at fs/f2fs/extent_cache.c:678! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 5336 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:__update_extent_tree_range+0x13bc/0x1500 fs/f2fs/extent_cache.c:678 Call Trace: f2fs_update_read_extent_cache_range+0x192/0x3e0 fs/f2fs/extent_cache.c:1085 f2fs_do_zero_range fs/f2fs/file.c:1657 [inline] f2fs_zero_range+0x10c1/0x1580 fs/f2fs/file.c:1737 f2fs_fallocate+0x583/0x990 fs/f2fs/file.c:2030 vfs_fallocate+0x669/0x7e0 fs/open.c:342 ioctl_preallocate fs/ioctl.c:289 [inline] file_ioctl+0x611/0x780 fs/ioctl.c:-1 do_vfs_ioctl+0xb33/0x1430 fs/ioctl.c:576 __do_sys_ioctl fs/ioctl.c:595 [inline] __se_sys_ioctl+0x82/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f07bc58eec9
In error path of f2fs_zero_range(), it may add a zero-sized extent into extent cache, it should be avoided.
{
"affected": [],
"aliases": [
"CVE-2025-68796"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-01-13T16:16:01Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix to avoid updating zero-sized extent in extent cache\n\nAs syzbot reported:\n\nF2FS-fs (loop0): __update_extent_tree_range: extent len is zero, type: 0, extent [0, 0, 0], age [0, 0]\n------------[ cut here ]------------\nkernel BUG at fs/f2fs/extent_cache.c:678!\nOops: invalid opcode: 0000 [#1] SMP KASAN NOPTI\nCPU: 0 UID: 0 PID: 5336 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full)\nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014\nRIP: 0010:__update_extent_tree_range+0x13bc/0x1500 fs/f2fs/extent_cache.c:678\nCall Trace:\n \u003cTASK\u003e\n f2fs_update_read_extent_cache_range+0x192/0x3e0 fs/f2fs/extent_cache.c:1085\n f2fs_do_zero_range fs/f2fs/file.c:1657 [inline]\n f2fs_zero_range+0x10c1/0x1580 fs/f2fs/file.c:1737\n f2fs_fallocate+0x583/0x990 fs/f2fs/file.c:2030\n vfs_fallocate+0x669/0x7e0 fs/open.c:342\n ioctl_preallocate fs/ioctl.c:289 [inline]\n file_ioctl+0x611/0x780 fs/ioctl.c:-1\n do_vfs_ioctl+0xb33/0x1430 fs/ioctl.c:576\n __do_sys_ioctl fs/ioctl.c:595 [inline]\n __se_sys_ioctl+0x82/0x170 fs/ioctl.c:583\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nRIP: 0033:0x7f07bc58eec9\n\nIn error path of f2fs_zero_range(), it may add a zero-sized extent\ninto extent cache, it should be avoided.",
"id": "GHSA-x84x-5w8g-xr7g",
"modified": "2026-01-19T15:30:35Z",
"published": "2026-01-13T18:31:04Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-68796"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4f244c64efe628d277b916f47071adf480eb8646"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/72c58a82e6fb7b327e8701f5786c70c3edc56188"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/7c37c79510329cd951a4dedf3f7bf7e2b18dccec"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9c07bd262c13ca922adad6e7613d48505f97f548"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/bac23833220a1f8fe8dfab7e16efa20ff64d7589"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e50b81c50fcbe63f50405bb40f262162ff32af88"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/efe3371001f50a2d6f746b50bdc6f9f26b2089ec"
}
],
"schema_version": "1.4.0",
"severity": []
}
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