| 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-2021-47638: ubifs: rename_whiteout: Fix double free for whiteout_ui->data |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| ubifs: rename_whiteout: Fix double free for whiteout_ui->data |
| |
| 'whiteout_ui->data' will be freed twice if space budget fail for |
| rename whiteout operation as following process: |
| |
| rename_whiteout |
| dev = kmalloc |
| whiteout_ui->data = dev |
| kfree(whiteout_ui->data) // Free first time |
| iput(whiteout) |
| ubifs_free_inode |
| kfree(ui->data) // Double free! |
| |
| KASAN reports: |
| ================================================================== |
| BUG: KASAN: double-free or invalid-free in ubifs_free_inode+0x4f/0x70 |
| Call Trace: |
| kfree+0x117/0x490 |
| ubifs_free_inode+0x4f/0x70 [ubifs] |
| i_callback+0x30/0x60 |
| rcu_do_batch+0x366/0xac0 |
| __do_softirq+0x133/0x57f |
| |
| Allocated by task 1506: |
| kmem_cache_alloc_trace+0x3c2/0x7a0 |
| do_rename+0x9b7/0x1150 [ubifs] |
| ubifs_rename+0x106/0x1f0 [ubifs] |
| do_syscall_64+0x35/0x80 |
| |
| Freed by task 1506: |
| kfree+0x117/0x490 |
| do_rename.cold+0x53/0x8a [ubifs] |
| ubifs_rename+0x106/0x1f0 [ubifs] |
| do_syscall_64+0x35/0x80 |
| |
| The buggy address belongs to the object at ffff88810238bed8 which |
| belongs to the cache kmalloc-8 of size 8 |
| ================================================================== |
| |
| Let ubifs_free_inode() free 'whiteout_ui->data'. BTW, delete unused |
| assignment 'whiteout_ui->data_len = 0', process 'ubifs_evict_inode() |
| -> ubifs_jnl_delete_inode() -> ubifs_jnl_write_inode()' doesn't need it |
| (because 'inc_nlink(whiteout)' won't be excuted by 'goto out_release', |
| and the nlink of whiteout inode is 0). |
| |
| The Linux kernel CVE team has assigned CVE-2021-47638 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 4.9 with commit 9e0a1fff8db56eaaebb74b4a3ef65f86811c4798 and fixed in 4.14.276 with commit 8b3c7be16f3f4dfd6e15ac651484e59d3fa36274 |
| Issue introduced in 4.9 with commit 9e0a1fff8db56eaaebb74b4a3ef65f86811c4798 and fixed in 4.19.238 with commit 2b3236ecf96db7af5836e1366ce39ace8ce832fa |
| Issue introduced in 4.9 with commit 9e0a1fff8db56eaaebb74b4a3ef65f86811c4798 and fixed in 5.4.189 with commit 14276d38c89a170363e90b6ac0a53c3cf61b87fc |
| Issue introduced in 4.9 with commit 9e0a1fff8db56eaaebb74b4a3ef65f86811c4798 and fixed in 5.10.110 with commit a90e2dbe66d2647ff95a0442ad2e86482d977fd8 |
| Issue introduced in 4.9 with commit 9e0a1fff8db56eaaebb74b4a3ef65f86811c4798 and fixed in 5.15.33 with commit 2ad07009c459e56ebdcc089d850d664660fdb742 |
| Issue introduced in 4.9 with commit 9e0a1fff8db56eaaebb74b4a3ef65f86811c4798 and fixed in 5.16.19 with commit b9a937f096e608b3368c1abc920d4d640ba2c94f |
| Issue introduced in 4.9 with commit 9e0a1fff8db56eaaebb74b4a3ef65f86811c4798 and fixed in 5.17.2 with commit 6d7a158a7363c1f6604aa47ae1a280a5c65123dd |
| Issue introduced in 4.9 with commit 9e0a1fff8db56eaaebb74b4a3ef65f86811c4798 and fixed in 5.18 with commit 40a8f0d5e7b3999f096570edab71c345da812e3e |
| |
| 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-2021-47638 |
| 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/ubifs/dir.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/8b3c7be16f3f4dfd6e15ac651484e59d3fa36274 |
| https://git.kernel.org/stable/c/2b3236ecf96db7af5836e1366ce39ace8ce832fa |
| https://git.kernel.org/stable/c/14276d38c89a170363e90b6ac0a53c3cf61b87fc |
| https://git.kernel.org/stable/c/a90e2dbe66d2647ff95a0442ad2e86482d977fd8 |
| https://git.kernel.org/stable/c/2ad07009c459e56ebdcc089d850d664660fdb742 |
| https://git.kernel.org/stable/c/b9a937f096e608b3368c1abc920d4d640ba2c94f |
| https://git.kernel.org/stable/c/6d7a158a7363c1f6604aa47ae1a280a5c65123dd |
| https://git.kernel.org/stable/c/40a8f0d5e7b3999f096570edab71c345da812e3e |
