| 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-2022-49456: bonding: fix missed rcu protection |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| bonding: fix missed rcu protection |
| |
| When removing the rcu_read_lock in bond_ethtool_get_ts_info() as |
| discussed [1], I didn't notice it could be called via setsockopt, |
| which doesn't hold rcu lock, as syzbot pointed: |
| |
| stack backtrace: |
| CPU: 0 PID: 3599 Comm: syz-executor317 Not tainted 5.18.0-rc5-syzkaller-01392-g01f4685797a5 #0 |
| Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 |
| Call Trace: |
| <TASK> |
| __dump_stack lib/dump_stack.c:88 [inline] |
| dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 |
| bond_option_active_slave_get_rcu include/net/bonding.h:353 [inline] |
| bond_ethtool_get_ts_info+0x32c/0x3a0 drivers/net/bonding/bond_main.c:5595 |
| __ethtool_get_ts_info+0x173/0x240 net/ethtool/common.c:554 |
| ethtool_get_phc_vclocks+0x99/0x110 net/ethtool/common.c:568 |
| sock_timestamping_bind_phc net/core/sock.c:869 [inline] |
| sock_set_timestamping+0x3a3/0x7e0 net/core/sock.c:916 |
| sock_setsockopt+0x543/0x2ec0 net/core/sock.c:1221 |
| __sys_setsockopt+0x55e/0x6a0 net/socket.c:2223 |
| __do_sys_setsockopt net/socket.c:2238 [inline] |
| __se_sys_setsockopt net/socket.c:2235 [inline] |
| __x64_sys_setsockopt+0xba/0x150 net/socket.c:2235 |
| do_syscall_x64 arch/x86/entry/common.c:50 [inline] |
| do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 |
| entry_SYSCALL_64_after_hwframe+0x44/0xae |
| RIP: 0033:0x7f8902c8eb39 |
| |
| Fix it by adding rcu_read_lock and take a ref on the real_dev. |
| Since dev_hold() and dev_put() can take NULL these days, we can |
| skip checking if real_dev exist. |
| |
| [1] https://lore.kernel.org/netdev/27565.1642742439@famine/ |
| |
| The Linux kernel CVE team has assigned CVE-2022-49456 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.17 with commit aa6034678e873db8bd5c5a4b73f8b88c469374d6 and fixed in 5.17.14 with commit 1b66a533c47d29b38af8e05fbb53b609a5ba3a4e |
| Issue introduced in 5.17 with commit aa6034678e873db8bd5c5a4b73f8b88c469374d6 and fixed in 5.18.3 with commit 85eed460681da71b359ed906bce4d800081db854 |
| Issue introduced in 5.17 with commit aa6034678e873db8bd5c5a4b73f8b88c469374d6 and fixed in 5.19 with commit 9b80ccda233fa6c59de411bf889cc4d0e028f2c7 |
| |
| 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-2022-49456 |
| 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: |
| drivers/net/bonding/bond_main.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/1b66a533c47d29b38af8e05fbb53b609a5ba3a4e |
| https://git.kernel.org/stable/c/85eed460681da71b359ed906bce4d800081db854 |
| https://git.kernel.org/stable/c/9b80ccda233fa6c59de411bf889cc4d0e028f2c7 |
