{"id":"CVE-2022-49456","state":"PUBLISHED","title":"bonding: fix missed rcu protection","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbonding: fix missed rcu protection\n\nWhen removing the rcu_read_lock in bond_ethtool_get_ts_info() as\ndiscussed [1], I didn't notice it could be called via setsockopt,\nwhich doesn't hold rcu lock, as syzbot pointed:\n\n  stack backtrace:\n  CPU: 0 PID: 3599 Comm: syz-executor317 Not tainted 5.18.0-rc5-syzkaller-01392-g01f4685797a5 #0\n  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011\n  Call Trace:\n   <TASK>\n   __dump_stack lib/dump_stack.c:88 [inline]\n   dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106\n   bond_option_active_slave_get_rcu include/net/bonding.h:353 [inline]\n   bond_ethtool_get_ts_info+0x32c/0x3a0 drivers/net/bonding/bond_main.c:5595\n   __ethtool_get_ts_info+0x173/0x240 net/ethtool/common.c:554\n   ethtool_get_phc_vclocks+0x99/0x110 net/ethtool/common.c:568\n   sock_timestamping_bind_phc net/core/sock.c:869 [inline]\n   sock_set_timestamping+0x3a3/0x7e0 net/core/sock.c:916\n   sock_setsockopt+0x543/0x2ec0 net/core/sock.c:1221\n   __sys_setsockopt+0x55e/0x6a0 net/socket.c:2223\n   __do_sys_setsockopt net/socket.c:2238 [inline]\n   __se_sys_setsockopt net/socket.c:2235 [inline]\n   __x64_sys_setsockopt+0xba/0x150 net/socket.c:2235\n   do_syscall_x64 arch/x86/entry/common.c:50 [inline]\n   do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80\n   entry_SYSCALL_64_after_hwframe+0x44/0xae\n  RIP: 0033:0x7f8902c8eb39\n\nFix it by adding rcu_read_lock and take a ref on the real_dev.\nSince dev_hold() and dev_put() can take NULL these days, we can\nskip checking if real_dev exist.\n\n[1] https://lore.kernel.org/netdev/27565.1642742439@famine/","publishedAt":"2025-02-26T02:13:04.787Z","updatedAt":"2026-08-05T08:55:14.980Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"aa6034678e873db8bd5c5a4b73f8b88c469374d6","status":"affected","lessThan":"1b66a533c47d29b38af8e05fbb53b609a5ba3a4e","versionType":"git"},{"version":"aa6034678e873db8bd5c5a4b73f8b88c469374d6","status":"affected","lessThan":"85eed460681da71b359ed906bce4d800081db854","versionType":"git"},{"version":"aa6034678e873db8bd5c5a4b73f8b88c469374d6","status":"affected","lessThan":"9b80ccda233fa6c59de411bf889cc4d0e028f2c7","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/bonding/bond_main.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.17","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.17","versionType":"semver"},{"version":"5.17.14","status":"unaffected","lessThanOrEqual":"5.17.*","versionType":"semver"},{"version":"5.18.3","status":"unaffected","lessThanOrEqual":"5.18.*","versionType":"semver"},{"version":"5.19","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/bonding/bond_main.c"]}],"references":["https://git.kernel.org/stable/c/1b66a533c47d29b38af8e05fbb53b609a5ba3a4e","https://git.kernel.org/stable/c/85eed460681da71b359ed906bce4d800081db854","https://git.kernel.org/stable/c/9b80ccda233fa6c59de411bf889cc4d0e028f2c7"],"weaknesses":[],"ingestedAt":"2026-10-29T20:05:26.763Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2022/49xxx/CVE-2022-49456.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2022-49456","state":"PUBLISHED","datePublished":"2025-02-26T02:13:04.787Z","dateUpdated":"2026-08-05T08:55:14.980Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-02-26T02:08:31.574Z"},"containers":{"cna":{"title":"bonding: fix missed rcu protection","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nbonding: fix missed rcu protection\n\nWhen removing the rcu_read_lock in bond_ethtool_get_ts_info() as\ndiscussed [1], I didn't notice it could be called via setsockopt,\nwhich doesn't hold rcu lock, as syzbot pointed:\n\n  stack backtrace:\n  CPU: 0 PID: 3599 Comm: syz-executor317 Not tainted 5.18.0-rc5-syzkaller-01392-g01f4685797a5 #0\n  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011\n  Call Trace:\n   <TASK>\n   __dump_stack lib/dump_stack.c:88 [inline]\n   dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106\n   bond_option_active_slave_get_rcu include/net/bonding.h:353 [inline]\n   bond_ethtool_get_ts_info+0x32c/0x3a0 drivers/net/bonding/bond_main.c:5595\n   __ethtool_get_ts_info+0x173/0x240 net/ethtool/common.c:554\n   ethtool_get_phc_vclocks+0x99/0x110 net/ethtool/common.c:568\n   sock_timestamping_bind_phc net/core/sock.c:869 [inline]\n   sock_set_timestamping+0x3a3/0x7e0 net/core/sock.c:916\n   sock_setsockopt+0x543/0x2ec0 net/core/sock.c:1221\n   __sys_setsockopt+0x55e/0x6a0 net/socket.c:2223\n   __do_sys_setsockopt net/socket.c:2238 [inline]\n   __se_sys_setsockopt net/socket.c:2235 [inline]\n   __x64_sys_setsockopt+0xba/0x150 net/socket.c:2235\n   do_syscall_x64 arch/x86/entry/common.c:50 [inline]\n   do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80\n   entry_SYSCALL_64_after_hwframe+0x44/0xae\n  RIP: 0033:0x7f8902c8eb39\n\nFix it by adding rcu_read_lock and take a ref on the real_dev.\nSince dev_hold() and dev_put() can take NULL these days, we can\nskip checking if real_dev exist.\n\n[1] https://lore.kernel.org/netdev/27565.1642742439@famine/"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"aa6034678e873db8bd5c5a4b73f8b88c469374d6","status":"affected","lessThan":"1b66a533c47d29b38af8e05fbb53b609a5ba3a4e","versionType":"git"},{"version":"aa6034678e873db8bd5c5a4b73f8b88c469374d6","status":"affected","lessThan":"85eed460681da71b359ed906bce4d800081db854","versionType":"git"},{"version":"aa6034678e873db8bd5c5a4b73f8b88c469374d6","status":"affected","lessThan":"9b80ccda233fa6c59de411bf889cc4d0e028f2c7","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/bonding/bond_main.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.17","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.17","versionType":"semver"},{"version":"5.17.14","status":"unaffected","lessThanOrEqual":"5.17.*","versionType":"semver"},{"version":"5.18.3","status":"unaffected","lessThanOrEqual":"5.18.*","versionType":"semver"},{"version":"5.19","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/bonding/bond_main.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/1b66a533c47d29b38af8e05fbb53b609a5ba3a4e"},{"url":"https://git.kernel.org/stable/c/85eed460681da71b359ed906bce4d800081db854"},{"url":"https://git.kernel.org/stable/c/9b80ccda233fa6c59de411bf889cc4d0e028f2c7"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The bug is reached via setsockopt(SO_TIMESTAMPING with SOF_TIMESTAMPING_BIND_PHC) on a socket bound to a bonding device, flowing through sock_timestamping_bind_phc → ethtool_get_phc_vclocks → bond_ethtool_get_ts_info. This is a local syscall path, not packet- or network-facing processing.\nAC:L - An attacker who can create and manage a bond (e.g. via user namespaces) controls both sides of the race: repeatedly calling setsockopt while releasing/changing the active slave. Missing RCU protection lets synchronize_rcu in bond_release complete and free struct slave while the reader still uses it.\nPR:L - SO_TIMESTAMPING requires no capability, and the first SO_BINDTODEVICE needs none. Creating/configuring a bond and enslaving interfaces needs only CAP_NET_ADMIN in the network namespace's user_ns, which is available to an unprivileged user via user namespaces.\nUI:N - Exploitation requires only attacker-controlled syscalls (setsockopt and netlink bond/slave operations); no victim action is needed.\nS:U - This is a standard in-kernel UAF/RCU bug in the bonding driver that can escalate privileges within the same kernel authority; it does not cross VM, IOMMU, or other security boundaries.\nC:H - Without RCU protection, concurrent slave release can free struct slave while bond_option_active_slave_get_rcu still reads slave->dev and later uses real_dev, yielding a use-after-free that can be leveraged for arbitrary kernel memory disclosure.\nI:H - The same UAF on the active-slave path enables heap reuse and control of freed object contents, which is exploitable for arbitrary write / control-flow hijacking in the kernel.\nA:H - Use-after-free of the slave/netdev path can cause kernel oops/panic, and even the unprotected rcu_dereference alone triggers lockdep warnings; availability impact is therefore High."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T08:55:14.980Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"5.17.14"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"5.18.3"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"5.19"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}