CVE-2026-31596

Summary

In the Linux kernel, the following vulnerability has been resolved:

ocfs2: handle invalid dinode in ocfs2_group_extend

[BUG] kernel BUG at fs/ocfs2/resize.c:308! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI RIP: 0010:ocfs2_group_extend+0x10aa/0x1ae0 fs/ocfs2/resize.c:308 Code: 8b8520ff ffff83f8 860f8580 030000e8 5cc3c1fe Call Trace: … ocfs2_ioctl+0x175/0x6e0 fs/ocfs2/ioctl.c:869 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x197/0x1e0 fs/ioctl.c:583 x64_sys_call+0x1144/0x26a0 arch/x86/include/generated/asm/syscalls_64.h:17 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x93/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e …

[CAUSE] ocfs2_group_extend() assumes that the global bitmap inode block returned from ocfs2_inode_lock() has already been validated and BUG_ONs when the signature is not a dinode. That assumption is too strong for crafted filesystems because the JBD2-managed buffer path can bypass structural validation and return an invalid dinode to the resize ioctl.

[FIX] Validate the dinode explicitly in ocfs2_group_extend(). If the global bitmap buffer does not contain a valid dinode, report filesystem corruption with ocfs2_error() and fail the resize operation instead of crashing the kernel.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux10995aa2451afa20b721cc7de856cae1a13dba57 < 7eafcf507fbd68f3276c00f6c02ef155ad69f79baffected
LinuxLinux10995aa2451afa20b721cc7de856cae1a13dba57 < fabfa6b81bd386154d7e59f8cd8f760f9e68b48caffected
LinuxLinux10995aa2451afa20b721cc7de856cae1a13dba57 < b328d8e7c437d0f026ba2c13788af6eae77700f1affected
LinuxLinux10995aa2451afa20b721cc7de856cae1a13dba57 < 6575f9fbf084502b7118a628425bf7866666498daffected
LinuxLinux10995aa2451afa20b721cc7de856cae1a13dba57 < 911b557dd7817460881fd51a03069b539c674d0eaffected
LinuxLinux10995aa2451afa20b721cc7de856cae1a13dba57 < e384a850a3370d89a7a446cdeccd964bfba2a302affected
LinuxLinux10995aa2451afa20b721cc7de856cae1a13dba57 < 10fb72c47aac446f12a4ccd962c7daa60cc890a1affected
LinuxLinux10995aa2451afa20b721cc7de856cae1a13dba57 < 41c6e9bc3a09539deab43957a3211d902a4818f0affected
LinuxLinux10995aa2451afa20b721cc7de856cae1a13dba57 < 4a1c0ddc6e7bcf2e9db0eeaab9340dcfe97f448faffected
LinuxLinux2.6.29affected
LinuxLinux0 < 2.6.29unaffected
LinuxLinux5.10.258 <= 5.10.*unaffected
LinuxLinux5.15.209 <= 5.15.*unaffected
LinuxLinux6.1.175 <= 6.1.*unaffected
LinuxLinux6.6.136 <= 6.6.*unaffected
LinuxLinux6.12.83 <= 6.12.*unaffected
LinuxLinux6.18.24 <= 6.18.*unaffected
LinuxLinux6.19.14 <= 6.19.*unaffected
LinuxLinux7.0.1 <= 7.0.*unaffected
LinuxLinux7.1 <= *unaffected

Weaknesses

References