| 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-2024-50265: ocfs2: remove entry once instead of null-ptr-dereference in ocfs2_xa_remove() |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| ocfs2: remove entry once instead of null-ptr-dereference in ocfs2_xa_remove() |
| |
| Syzkaller is able to provoke null-ptr-dereference in ocfs2_xa_remove(): |
| |
| [ 57.319872] (a.out,1161,7):ocfs2_xa_remove:2028 ERROR: status = -12 |
| [ 57.320420] (a.out,1161,7):ocfs2_xa_cleanup_value_truncate:1999 ERROR: Partial truncate while removing xattr overlay.upper. Leaking 1 clusters and removing the entry |
| [ 57.321727] BUG: kernel NULL pointer dereference, address: 0000000000000004 |
| [...] |
| [ 57.325727] RIP: 0010:ocfs2_xa_block_wipe_namevalue+0x2a/0xc0 |
| [...] |
| [ 57.331328] Call Trace: |
| [ 57.331477] <TASK> |
| [...] |
| [ 57.333511] ? do_user_addr_fault+0x3e5/0x740 |
| [ 57.333778] ? exc_page_fault+0x70/0x170 |
| [ 57.334016] ? asm_exc_page_fault+0x2b/0x30 |
| [ 57.334263] ? __pfx_ocfs2_xa_block_wipe_namevalue+0x10/0x10 |
| [ 57.334596] ? ocfs2_xa_block_wipe_namevalue+0x2a/0xc0 |
| [ 57.334913] ocfs2_xa_remove_entry+0x23/0xc0 |
| [ 57.335164] ocfs2_xa_set+0x704/0xcf0 |
| [ 57.335381] ? _raw_spin_unlock+0x1a/0x40 |
| [ 57.335620] ? ocfs2_inode_cache_unlock+0x16/0x20 |
| [ 57.335915] ? trace_preempt_on+0x1e/0x70 |
| [ 57.336153] ? start_this_handle+0x16c/0x500 |
| [ 57.336410] ? preempt_count_sub+0x50/0x80 |
| [ 57.336656] ? _raw_read_unlock+0x20/0x40 |
| [ 57.336906] ? start_this_handle+0x16c/0x500 |
| [ 57.337162] ocfs2_xattr_block_set+0xa6/0x1e0 |
| [ 57.337424] __ocfs2_xattr_set_handle+0x1fd/0x5d0 |
| [ 57.337706] ? ocfs2_start_trans+0x13d/0x290 |
| [ 57.337971] ocfs2_xattr_set+0xb13/0xfb0 |
| [ 57.338207] ? dput+0x46/0x1c0 |
| [ 57.338393] ocfs2_xattr_trusted_set+0x28/0x30 |
| [ 57.338665] ? ocfs2_xattr_trusted_set+0x28/0x30 |
| [ 57.338948] __vfs_removexattr+0x92/0xc0 |
| [ 57.339182] __vfs_removexattr_locked+0xd5/0x190 |
| [ 57.339456] ? preempt_count_sub+0x50/0x80 |
| [ 57.339705] vfs_removexattr+0x5f/0x100 |
| [...] |
| |
| Reproducer uses faultinject facility to fail ocfs2_xa_remove() -> |
| ocfs2_xa_value_truncate() with -ENOMEM. |
| |
| In this case the comment mentions that we can return 0 if |
| ocfs2_xa_cleanup_value_truncate() is going to wipe the entry |
| anyway. But the following 'rc' check is wrong and execution flow do |
| 'ocfs2_xa_remove_entry(loc);' twice: |
| * 1st: in ocfs2_xa_cleanup_value_truncate(); |
| * 2nd: returning back to ocfs2_xa_remove() instead of going to 'out'. |
| |
| Fix this by skipping the 2nd removal of the same entry and making |
| syzkaller repro happy. |
| |
| The Linux kernel CVE team has assigned CVE-2024-50265 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 2.6.34 with commit 399ff3a748cf4c8c853e96dd477153202636527b and fixed in 4.19.324 with commit 38cbf13b2e7a31362babe411f7c2c3c52cd2734b |
| Issue introduced in 2.6.34 with commit 399ff3a748cf4c8c853e96dd477153202636527b and fixed in 5.4.286 with commit 168a9b8303fcb0317db4c06b23ce1c0ce2af4e10 |
| Issue introduced in 2.6.34 with commit 399ff3a748cf4c8c853e96dd477153202636527b and fixed in 5.10.230 with commit 6a7e6dcf90fe7721d0863067b6ca9a9442134692 |
| Issue introduced in 2.6.34 with commit 399ff3a748cf4c8c853e96dd477153202636527b and fixed in 5.15.172 with commit dcc8fe8c83145041cb6c80cac21f6173a3ff0204 |
| Issue introduced in 2.6.34 with commit 399ff3a748cf4c8c853e96dd477153202636527b and fixed in 6.1.117 with commit 86dd0e8d42828923c68ad506933336bcd6f2317d |
| Issue introduced in 2.6.34 with commit 399ff3a748cf4c8c853e96dd477153202636527b and fixed in 6.6.61 with commit dd73c942eed76a014c7a5597e6926435274d2c4c |
| Issue introduced in 2.6.34 with commit 399ff3a748cf4c8c853e96dd477153202636527b and fixed in 6.11.8 with commit 2b5369528ee63c88371816178a05b5e664c87386 |
| Issue introduced in 2.6.34 with commit 399ff3a748cf4c8c853e96dd477153202636527b and fixed in 6.12 with commit 0b63c0e01fba40e3992bc627272ec7b618ccaef7 |
| |
| 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-2024-50265 |
| 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/ocfs2/xattr.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/38cbf13b2e7a31362babe411f7c2c3c52cd2734b |
| https://git.kernel.org/stable/c/168a9b8303fcb0317db4c06b23ce1c0ce2af4e10 |
| https://git.kernel.org/stable/c/6a7e6dcf90fe7721d0863067b6ca9a9442134692 |
| https://git.kernel.org/stable/c/dcc8fe8c83145041cb6c80cac21f6173a3ff0204 |
| https://git.kernel.org/stable/c/86dd0e8d42828923c68ad506933336bcd6f2317d |
| https://git.kernel.org/stable/c/dd73c942eed76a014c7a5597e6926435274d2c4c |
| https://git.kernel.org/stable/c/2b5369528ee63c88371816178a05b5e664c87386 |
| https://git.kernel.org/stable/c/0b63c0e01fba40e3992bc627272ec7b618ccaef7 |
