Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: block: Avoid mounting the bdev pseudo-filesystem in userspace The bdev pseudo-filesystem is an internal kernel filesystem with which userspace should not interfere. Unregister it so that userspace cannot even attempt to mount it. This fixes a bug [1] that occurs when attempting to access files, because the system call move_mount() uses pointers declared in the inode_operations structure, which for the bdev pseudo-filesystem are always equal to 0. `inode->i_op = &empty_iops;` [1] BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD 23380067 P4D 23380067 PUD 23381067 PMD 0 Oops: 0010 [#1] PREEMPT SMP KASAN NOPTI CPU: 2 PID: 17125 Comm: syz-executor.0 Not tainted 6.1.155-syzkaller-00350-g84221fde2681 #0 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:0x0 Call Trace: <TASK> lookup_open.isra.0+0x700/0x1180 fs/namei.c:3460 open_last_lookups fs/namei.c:3550 [inline] path_openat+0x953/0x2700 fs/namei.c:3780 do_filp_open+0x1c5/0x410 fs/namei.c:3810 do_sys_openat2+0x171/0x4d0 fs/open.c:1318 do_sys_open fs/open.c:1334 [inline] __do_sys_openat fs/open.c:1350 [inline] __se_sys_openat fs/open.c:1345 [inline] __x64_sys_openat+0x13c/0x1f0 fs/open.c:1345 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x35/0x80 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 3d3fcf23993bb756de2f912ab631cfdcc4746554; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 99cde0a7b1e98fd3970aabef1300918e91698dd5; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 1a02a5028bd6dead1f8503854ef3168d651cd417; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 197971e6ffc0a6356b2ba2b22beb42bc0f7e412d; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 3804e6de30ae7b053d53341d9d6944356cf23b40; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 717f721eb67d2dacd3ed5f7495aef2f442e84ce4; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before f73aa66dffcb8e61e78f01b56163ec16a15d06d2 |
| Linux / Linux | affected 2.6.12; unaffected 0 before 2.6.12; unaffected 5.15.212 through 5.15.*; unaffected 6.1.178 through 6.1.*; unaffected 6.6.145 through 6.6.*; unaffected 6.12.95 through 6.12.*; unaffected 6.18.38 through 6.18.*; unaffected 7.1.3 through 7.1.*; unaffected 7.2 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/3d3fcf23993bb756de2f912ab631cfdcc4746554
- https://git.kernel.org/stable/c/99cde0a7b1e98fd3970aabef1300918e91698dd5
- https://git.kernel.org/stable/c/1a02a5028bd6dead1f8503854ef3168d651cd417
- https://git.kernel.org/stable/c/197971e6ffc0a6356b2ba2b22beb42bc0f7e412d
- https://git.kernel.org/stable/c/3804e6de30ae7b053d53341d9d6944356cf23b40
- https://git.kernel.org/stable/c/717f721eb67d2dacd3ed5f7495aef2f442e84ce4
- https://git.kernel.org/stable/c/f73aa66dffcb8e61e78f01b56163ec16a15d06d2
ADP enrichment
No English description supplied.