| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2024-35832: bcachefs: kvfree bch_fs::snapshots in bch2_fs_snapshots_exit |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| bcachefs: kvfree bch_fs::snapshots in bch2_fs_snapshots_exit |
| |
| bch_fs::snapshots is allocated by kvzalloc in __snapshot_t_mut. |
| It should be freed by kvfree not kfree. |
| Or umount will triger: |
| |
| [ 406.829178 ] BUG: unable to handle page fault for address: ffffe7b487148008 |
| [ 406.830676 ] #PF: supervisor read access in kernel mode |
| [ 406.831643 ] #PF: error_code(0x0000) - not-present page |
| [ 406.832487 ] PGD 0 P4D 0 |
| [ 406.832898 ] Oops: 0000 [#1] PREEMPT SMP PTI |
| [ 406.833512 ] CPU: 2 PID: 1754 Comm: umount Kdump: loaded Tainted: G OE 6.7.0-rc7-custom+ #90 |
| [ 406.834746 ] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014 |
| [ 406.835796 ] RIP: 0010:kfree+0x62/0x140 |
| [ 406.836197 ] Code: 80 48 01 d8 0f 82 e9 00 00 00 48 c7 c2 00 00 00 80 48 2b 15 78 9f 1f 01 48 01 d0 48 c1 e8 0c 48 c1 e0 06 48 03 05 56 9f 1f 01 <48> 8b 50 08 48 89 c7 f6 c2 01 0f 85 b0 00 00 00 66 90 48 8b 07 f6 |
| [ 406.837810 ] RSP: 0018:ffffb9d641607e48 EFLAGS: 00010286 |
| [ 406.838213 ] RAX: ffffe7b487148000 RBX: ffffb9d645200000 RCX: ffffb9d641607dc4 |
| [ 406.838738 ] RDX: 000065bb00000000 RSI: ffffffffc0d88b84 RDI: ffffb9d645200000 |
| [ 406.839217 ] RBP: ffff9a4625d00068 R08: 0000000000000001 R09: 0000000000000001 |
| [ 406.839650 ] R10: 0000000000000001 R11: 000000000000001f R12: ffff9a4625d4da80 |
| [ 406.840055 ] R13: ffff9a4625d00000 R14: ffffffffc0e2eb20 R15: 0000000000000000 |
| [ 406.840451 ] FS: 00007f0a264ffb80(0000) GS:ffff9a4e2d500000(0000) knlGS:0000000000000000 |
| [ 406.840851 ] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 |
| [ 406.841125 ] CR2: ffffe7b487148008 CR3: 000000018c4d2000 CR4: 00000000000006f0 |
| [ 406.841464 ] Call Trace: |
| [ 406.841583 ] <TASK> |
| [ 406.841682 ] ? __die+0x1f/0x70 |
| [ 406.841828 ] ? page_fault_oops+0x159/0x470 |
| [ 406.842014 ] ? fixup_exception+0x22/0x310 |
| [ 406.842198 ] ? exc_page_fault+0x1ed/0x200 |
| [ 406.842382 ] ? asm_exc_page_fault+0x22/0x30 |
| [ 406.842574 ] ? bch2_fs_release+0x54/0x280 [bcachefs] |
| [ 406.842842 ] ? kfree+0x62/0x140 |
| [ 406.842988 ] ? kfree+0x104/0x140 |
| [ 406.843138 ] bch2_fs_release+0x54/0x280 [bcachefs] |
| [ 406.843390 ] kobject_put+0xb7/0x170 |
| [ 406.843552 ] deactivate_locked_super+0x2f/0xa0 |
| [ 406.843756 ] cleanup_mnt+0xba/0x150 |
| [ 406.843917 ] task_work_run+0x59/0xa0 |
| [ 406.844083 ] exit_to_user_mode_prepare+0x197/0x1a0 |
| [ 406.844302 ] syscall_exit_to_user_mode+0x16/0x40 |
| [ 406.844510 ] do_syscall_64+0x4e/0xf0 |
| [ 406.844675 ] entry_SYSCALL_64_after_hwframe+0x6e/0x76 |
| [ 406.844907 ] RIP: 0033:0x7f0a2664e4fb |
| |
| The Linux kernel CVE team has assigned CVE-2024-35832 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.7 with commit 1c6fdbd8f2465ddfb73a01ec620cbf3d14044e1a and fixed in 6.7.5 with commit 56590678791119b9a655202e49898edfb9307271 |
| Issue introduced in 6.7 with commit 1c6fdbd8f2465ddfb73a01ec620cbf3d14044e1a and fixed in 6.8 with commit 369acf97d6fd5da620d053d0f1878ffe32eff555 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2024-35832 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| fs/bcachefs/snapshot.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/56590678791119b9a655202e49898edfb9307271 |
| https://git.kernel.org/stable/c/369acf97d6fd5da620d053d0f1878ffe32eff555 |
