CVE-2026-53039

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

ocfs2: validate group add input before caching

[BUG]

OCFS2_IOC_GROUP_ADD can trigger a BUG_ON in

ocfs2_set_new_buffer_uptodate():

kernel BUG at fs/ocfs2/uptodate.c:509!

Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI

RIP: 0010:ocfs2_set_new_buffer_uptodate+0x194/0x1e0 fs/ocfs2/uptodate.c:509

Code: ffffe88f 42b9fe4c 89e64889 dfe8b4df

Call Trace:

ocfs2_group_add+0x3f1/0x1510 fs/ocfs2/resize.c:507

ocfs2_ioctl+0x309/0x6e0 fs/ocfs2/ioctl.c:887

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

RIP: 0033:0x7bbfb55a966d

[CAUSE]

ocfs2_group_add() calls ocfs2_set_new_buffer_uptodate() on a

user-controlled group block before ocfs2_verify_group_and_input()

validates that block number. That helper is only valid for newly

allocated metadata and asserts that the block is not already present in

the chosen metadata cache. The code also uses INODE_CACHE(inode) even

though the group descriptor belongs to main_bm_inode and later journal

accesses use that cache context instead.

[FIX]

Validate the on-disk group descriptor before caching it, then add it to

the metadata cache tracked by INODE_CACHE(main_bm_inode). Keep the

validation failure path separate from the later cleanup path so we only

remove the buffer from that cache after it has actually been inserted.

This keeps the group buffer lifetime consistent across validation,

journaling, and cleanup.