Bug 2422711 (CVE-2025-40357)
| Summary: | CVE-2025-40357 kernel: net/smc: fix general protection fault in __smc_diag_dump | ||
|---|---|---|---|
| Product: | [Other] Security Response | Reporter: | OSIDB Bzimport <bzimport> |
| Component: | vulnerability | Assignee: | Product Security DevOps Team <prodsec-dev> |
| Status: | NEW --- | QA Contact: | |
| Severity: | low | Docs Contact: | |
| Priority: | low | ||
| Version: | unspecified | Keywords: | Security |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | --- | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | Type: | --- | |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
In the Linux kernel, the following vulnerability has been resolved: net/smc: fix general protection fault in __smc_diag_dump The syzbot report a crash: Oops: general protection fault, probably for non-canonical address 0xfbd5a5d5a0000003: 0000 [#1] SMP KASAN NOPTI KASAN: maybe wild-memory-access in range [0xdead4ead00000018-0xdead4ead0000001f] CPU: 1 UID: 0 PID: 6949 Comm: syz.0.335 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:smc_diag_msg_common_fill net/smc/smc_diag.c:44 [inline] RIP: 0010:__smc_diag_dump.constprop.0+0x3ca/0x2550 net/smc/smc_diag.c:89 Call Trace: <TASK> smc_diag_dump_proto+0x26d/0x420 net/smc/smc_diag.c:217 smc_diag_dump+0x27/0x90 net/smc/smc_diag.c:234 netlink_dump+0x539/0xd30 net/netlink/af_netlink.c:2327 __netlink_dump_start+0x6d6/0x990 net/netlink/af_netlink.c:2442 netlink_dump_start include/linux/netlink.h:341 [inline] smc_diag_handler_dump+0x1f9/0x240 net/smc/smc_diag.c:251 __sock_diag_cmd net/core/sock_diag.c:249 [inline] sock_diag_rcv_msg+0x438/0x790 net/core/sock_diag.c:285 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x5a7/0x870 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg net/socket.c:729 [inline] ____sys_sendmsg+0xa95/0xc70 net/socket.c:2614 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2668 __sys_sendmsg+0x16d/0x220 net/socket.c:2700 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f </TASK> The process like this: (CPU1) | (CPU2) ---------------------------------|------------------------------- inet_create() | // init clcsock to NULL | sk = sk_alloc() | | // unexpectedly change clcsock | inet_init_csk_locks() | | // add sk to hash table | smc_inet_init_sock() | smc_sk_init() | smc_hash_sk() | | // traverse the hash table | smc_diag_dump_proto | __smc_diag_dump() | // visit wrong clcsock | smc_diag_msg_common_fill() // alloc clcsock | smc_create_clcsk | sock_create_kern | With CONFIG_DEBUG_LOCK_ALLOC=y, the smc->clcsock is unexpectedly changed in inet_init_csk_locks(). The INET_PROTOSW_ICSK flag is no need by smc, just remove it. After removing the INET_PROTOSW_ICSK flag, this patch alse revert commit 6fd27ea183c2 ("net/smc: fix lacks of icsk_syn_mss with IPPROTO_SMC") to avoid casting smc_sock to inet_connection_sock.