| 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-2024-44934: net: bridge: mcast: wait for previous gc cycles when removing port |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| net: bridge: mcast: wait for previous gc cycles when removing port |
| |
| syzbot hit a use-after-free[1] which is caused because the bridge doesn't |
| make sure that all previous garbage has been collected when removing a |
| port. What happens is: |
| CPU 1 CPU 2 |
| start gc cycle remove port |
| acquire gc lock first |
| wait for lock |
| call br_multicasg_gc() directly |
| acquire lock now but free port |
| the port can be freed |
| while grp timers still |
| running |
| |
| Make sure all previous gc cycles have finished by using flush_work before |
| freeing the port. |
| |
| [1] |
| BUG: KASAN: slab-use-after-free in br_multicast_port_group_expired+0x4c0/0x550 net/bridge/br_multicast.c:861 |
| Read of size 8 at addr ffff888071d6d000 by task syz.5.1232/9699 |
| |
| CPU: 1 PID: 9699 Comm: syz.5.1232 Not tainted 6.10.0-rc5-syzkaller-00021-g24ca36a562d6 #0 |
| Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 |
| Call Trace: |
| <IRQ> |
| __dump_stack lib/dump_stack.c:88 [inline] |
| dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 |
| print_address_description mm/kasan/report.c:377 [inline] |
| print_report+0xc3/0x620 mm/kasan/report.c:488 |
| kasan_report+0xd9/0x110 mm/kasan/report.c:601 |
| br_multicast_port_group_expired+0x4c0/0x550 net/bridge/br_multicast.c:861 |
| call_timer_fn+0x1a3/0x610 kernel/time/timer.c:1792 |
| expire_timers kernel/time/timer.c:1843 [inline] |
| __run_timers+0x74b/0xaf0 kernel/time/timer.c:2417 |
| __run_timer_base kernel/time/timer.c:2428 [inline] |
| __run_timer_base kernel/time/timer.c:2421 [inline] |
| run_timer_base+0x111/0x190 kernel/time/timer.c:2437 |
| |
| The Linux kernel CVE team has assigned CVE-2024-44934 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.10 with commit e12cec65b5546f19217e26aafb8add6e2fadca18 and fixed in 5.15.165 with commit 1e16828020c674b3be85f52685e8b80f9008f50f |
| Issue introduced in 5.10 with commit e12cec65b5546f19217e26aafb8add6e2fadca18 and fixed in 6.1.105 with commit 0d8b26e10e680c01522d7cc14abe04c3265a928f |
| Issue introduced in 5.10 with commit e12cec65b5546f19217e26aafb8add6e2fadca18 and fixed in 6.6.46 with commit e3145ca904fa8dbfd1a5bf0187905bc117b0efce |
| Issue introduced in 5.10 with commit e12cec65b5546f19217e26aafb8add6e2fadca18 and fixed in 6.10.5 with commit b2f794b168cf560682ff976b255aa6d29d14a658 |
| Issue introduced in 5.10 with commit e12cec65b5546f19217e26aafb8add6e2fadca18 and fixed in 6.11 with commit 92c4ee25208d0f35dafc3213cdf355fbe449e078 |
| |
| 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-2024-44934 |
| 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: |
| net/bridge/br_multicast.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/1e16828020c674b3be85f52685e8b80f9008f50f |
| https://git.kernel.org/stable/c/0d8b26e10e680c01522d7cc14abe04c3265a928f |
| https://git.kernel.org/stable/c/e3145ca904fa8dbfd1a5bf0187905bc117b0efce |
| https://git.kernel.org/stable/c/b2f794b168cf560682ff976b255aa6d29d14a658 |
| https://git.kernel.org/stable/c/92c4ee25208d0f35dafc3213cdf355fbe449e078 |
