| Message ID | 20241107192021.2579789-1-edumazet@google.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | eb72e7fcc83987d5d5595b43222f23b295d5de7f |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next] sctp: fix possible UAF in sctp_v6_available() | expand |
On Thu, Nov 7, 2024 at 2:20 PM Eric Dumazet <edumazet@google.com> wrote: > > A lockdep report [1] with CONFIG_PROVE_RCU_LIST=y hints > that sctp_v6_available() is calling dev_get_by_index_rcu() > and ipv6_chk_addr() without holding rcu. > > [1] > ============================= > WARNING: suspicious RCU usage > 6.12.0-rc5-virtme #1216 Tainted: G W > ----------------------------- > net/core/dev.c:876 RCU-list traversed in non-reader section!! > > other info that might help us debug this: > > rcu_scheduler_active = 2, debug_locks = 1 > 1 lock held by sctp_hello/31495: > #0: ffff9f1ebbdb7418 (sk_lock-AF_INET6){+.+.}-{0:0}, at: sctp_bind (./arch/x86/include/asm/jump_label.h:27 net/sctp/socket.c:315) sctp > > stack backtrace: > CPU: 7 UID: 0 PID: 31495 Comm: sctp_hello Tainted: G W 6.12.0-rc5-virtme #1216 > Tainted: [W]=WARN > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 > Call Trace: > <TASK> > dump_stack_lvl (lib/dump_stack.c:123) > lockdep_rcu_suspicious (kernel/locking/lockdep.c:6822) > dev_get_by_index_rcu (net/core/dev.c:876 (discriminator 7)) > sctp_v6_available (net/sctp/ipv6.c:701) sctp > sctp_do_bind (net/sctp/socket.c:400 (discriminator 1)) sctp > sctp_bind (net/sctp/socket.c:320) sctp > inet6_bind_sk (net/ipv6/af_inet6.c:465) > ? security_socket_bind (security/security.c:4581 (discriminator 1)) > __sys_bind (net/socket.c:1848 net/socket.c:1869) > ? do_user_addr_fault (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 ./include/linux/mm.h:729 arch/x86/mm/fault.c:1340) > ? do_user_addr_fault (./arch/x86/include/asm/preempt.h:84 (discriminator 13) ./include/linux/rcupdate.h:98 (discriminator 13) ./include/linux/rcupdate.h:882 (discriminator 13) ./include/linux/mm.h:729 (discriminator 13) arch/x86/mm/fault.c:1340 (discriminator 13)) > __x64_sys_bind (net/socket.c:1877 (discriminator 1) net/socket.c:1875 (discriminator 1) net/socket.c:1875 (discriminator 1)) > do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1) arch/x86/entry/common.c:83 (discriminator 1)) > entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) > RIP: 0033:0x7f59b934a1e7 > Code: 44 00 00 48 8b 15 39 8c 0c 00 f7 d8 64 89 02 b8 ff ff ff ff eb bd 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 b8 31 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 09 8c 0c 00 f7 d8 64 89 01 48 > All code > ======== > 0: 44 00 00 add %r8b,(%rax) > 3: 48 8b 15 39 8c 0c 00 mov 0xc8c39(%rip),%rdx # 0xc8c43 > a: f7 d8 neg %eax > c: 64 89 02 mov %eax,%fs:(%rdx) > f: b8 ff ff ff ff mov $0xffffffff,%eax > 14: eb bd jmp 0xffffffffffffffd3 > 16: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) > 1d: 00 00 00 > 20: 0f 1f 00 nopl (%rax) > 23: b8 31 00 00 00 mov $0x31,%eax > 28: 0f 05 syscall > 2a:* 48 3d 01 f0 ff ff cmp $0xfffffffffffff001,%rax <-- trapping instruction > 30: 73 01 jae 0x33 > 32: c3 ret > 33: 48 8b 0d 09 8c 0c 00 mov 0xc8c09(%rip),%rcx # 0xc8c43 > 3a: f7 d8 neg %eax > 3c: 64 89 01 mov %eax,%fs:(%rcx) > 3f: 48 rex.W > > Code starting with the faulting instruction > =========================================== > 0: 48 3d 01 f0 ff ff cmp $0xfffffffffffff001,%rax > 6: 73 01 jae 0x9 > 8: c3 ret > 9: 48 8b 0d 09 8c 0c 00 mov 0xc8c09(%rip),%rcx # 0xc8c19 > 10: f7 d8 neg %eax > 12: 64 89 01 mov %eax,%fs:(%rcx) > 15: 48 rex.W > RSP: 002b:00007ffe2d0ad398 EFLAGS: 00000202 ORIG_RAX: 0000000000000031 > RAX: ffffffffffffffda RBX: 00007ffe2d0ad3d0 RCX: 00007f59b934a1e7 > RDX: 000000000000001c RSI: 00007ffe2d0ad3d0 RDI: 0000000000000005 > RBP: 0000000000000005 R08: 1999999999999999 R09: 0000000000000000 > R10: 00007f59b9253298 R11: 0000000000000202 R12: 00007ffe2d0ada61 > R13: 0000000000000000 R14: 0000562926516dd8 R15: 00007f59b9479000 > </TASK> > > Fixes: 6fe1e52490a9 ("sctp: check ipv6 addr with sk_bound_dev if set") > Signed-off-by: Eric Dumazet <edumazet@google.com> > Cc: Xin Long <lucien.xin@gmail.com> > Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Xin Long <lucien.xin@gmail.com> > --- > net/sctp/ipv6.c | 19 +++++++++++++------ > 1 file changed, 13 insertions(+), 6 deletions(-) > > diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c > index f7b809c0d142c0e6c8e29c2badc4428648117f31..38e2fbdcbeac4bf3185d98f8acae4aea531ca140 100644 > --- a/net/sctp/ipv6.c > +++ b/net/sctp/ipv6.c > @@ -683,7 +683,7 @@ static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp) > struct sock *sk = &sp->inet.sk; > struct net *net = sock_net(sk); > struct net_device *dev = NULL; > - int type; > + int type, res, bound_dev_if; > > type = ipv6_addr_type(in6); > if (IPV6_ADDR_ANY == type) > @@ -697,14 +697,21 @@ static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp) > if (!(type & IPV6_ADDR_UNICAST)) > return 0; > > - if (sk->sk_bound_dev_if) { > - dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if); > + rcu_read_lock(); > + bound_dev_if = READ_ONCE(sk->sk_bound_dev_if); > + if (bound_dev_if) { > + res = 0; > + dev = dev_get_by_index_rcu(net, bound_dev_if); > if (!dev) > - return 0; > + goto out; > } > > - return ipv6_can_nonlocal_bind(net, &sp->inet) || > - ipv6_chk_addr(net, in6, dev, 0); > + res = ipv6_can_nonlocal_bind(net, &sp->inet) || > + ipv6_chk_addr(net, in6, dev, 0); > + > +out: > + rcu_read_unlock(); > + return res; > } > > /* This function checks if the address is a valid address to be used for > -- > 2.47.0.277.g8800431eea-goog >
Hello: This patch was applied to netdev/net.git (main) by Jakub Kicinski <kuba@kernel.org>: On Thu, 7 Nov 2024 19:20:21 +0000 you wrote: > A lockdep report [1] with CONFIG_PROVE_RCU_LIST=y hints > that sctp_v6_available() is calling dev_get_by_index_rcu() > and ipv6_chk_addr() without holding rcu. > > [1] > ============================= > WARNING: suspicious RCU usage > 6.12.0-rc5-virtme #1216 Tainted: G W > > [...] Here is the summary with links: - [net-next] sctp: fix possible UAF in sctp_v6_available() https://git.kernel.org/netdev/net/c/eb72e7fcc839 You are awesome, thank you!
diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c index f7b809c0d142c0e6c8e29c2badc4428648117f31..38e2fbdcbeac4bf3185d98f8acae4aea531ca140 100644 --- a/net/sctp/ipv6.c +++ b/net/sctp/ipv6.c @@ -683,7 +683,7 @@ static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp) struct sock *sk = &sp->inet.sk; struct net *net = sock_net(sk); struct net_device *dev = NULL; - int type; + int type, res, bound_dev_if; type = ipv6_addr_type(in6); if (IPV6_ADDR_ANY == type) @@ -697,14 +697,21 @@ static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp) if (!(type & IPV6_ADDR_UNICAST)) return 0; - if (sk->sk_bound_dev_if) { - dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if); + rcu_read_lock(); + bound_dev_if = READ_ONCE(sk->sk_bound_dev_if); + if (bound_dev_if) { + res = 0; + dev = dev_get_by_index_rcu(net, bound_dev_if); if (!dev) - return 0; + goto out; } - return ipv6_can_nonlocal_bind(net, &sp->inet) || - ipv6_chk_addr(net, in6, dev, 0); + res = ipv6_can_nonlocal_bind(net, &sp->inet) || + ipv6_chk_addr(net, in6, dev, 0); + +out: + rcu_read_unlock(); + return res; } /* This function checks if the address is a valid address to be used for
A lockdep report [1] with CONFIG_PROVE_RCU_LIST=y hints that sctp_v6_available() is calling dev_get_by_index_rcu() and ipv6_chk_addr() without holding rcu. [1] ============================= WARNING: suspicious RCU usage 6.12.0-rc5-virtme #1216 Tainted: G W ----------------------------- net/core/dev.c:876 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by sctp_hello/31495: #0: ffff9f1ebbdb7418 (sk_lock-AF_INET6){+.+.}-{0:0}, at: sctp_bind (./arch/x86/include/asm/jump_label.h:27 net/sctp/socket.c:315) sctp stack backtrace: CPU: 7 UID: 0 PID: 31495 Comm: sctp_hello Tainted: G W 6.12.0-rc5-virtme #1216 Tainted: [W]=WARN Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: <TASK> dump_stack_lvl (lib/dump_stack.c:123) lockdep_rcu_suspicious (kernel/locking/lockdep.c:6822) dev_get_by_index_rcu (net/core/dev.c:876 (discriminator 7)) sctp_v6_available (net/sctp/ipv6.c:701) sctp sctp_do_bind (net/sctp/socket.c:400 (discriminator 1)) sctp sctp_bind (net/sctp/socket.c:320) sctp inet6_bind_sk (net/ipv6/af_inet6.c:465) ? security_socket_bind (security/security.c:4581 (discriminator 1)) __sys_bind (net/socket.c:1848 net/socket.c:1869) ? do_user_addr_fault (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 ./include/linux/mm.h:729 arch/x86/mm/fault.c:1340) ? do_user_addr_fault (./arch/x86/include/asm/preempt.h:84 (discriminator 13) ./include/linux/rcupdate.h:98 (discriminator 13) ./include/linux/rcupdate.h:882 (discriminator 13) ./include/linux/mm.h:729 (discriminator 13) arch/x86/mm/fault.c:1340 (discriminator 13)) __x64_sys_bind (net/socket.c:1877 (discriminator 1) net/socket.c:1875 (discriminator 1) net/socket.c:1875 (discriminator 1)) do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1) arch/x86/entry/common.c:83 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) RIP: 0033:0x7f59b934a1e7 Code: 44 00 00 48 8b 15 39 8c 0c 00 f7 d8 64 89 02 b8 ff ff ff ff eb bd 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 b8 31 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 09 8c 0c 00 f7 d8 64 89 01 48 All code ======== 0: 44 00 00 add %r8b,(%rax) 3: 48 8b 15 39 8c 0c 00 mov 0xc8c39(%rip),%rdx # 0xc8c43 a: f7 d8 neg %eax c: 64 89 02 mov %eax,%fs:(%rdx) f: b8 ff ff ff ff mov $0xffffffff,%eax 14: eb bd jmp 0xffffffffffffffd3 16: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) 1d: 00 00 00 20: 0f 1f 00 nopl (%rax) 23: b8 31 00 00 00 mov $0x31,%eax 28: 0f 05 syscall 2a:* 48 3d 01 f0 ff ff cmp $0xfffffffffffff001,%rax <-- trapping instruction 30: 73 01 jae 0x33 32: c3 ret 33: 48 8b 0d 09 8c 0c 00 mov 0xc8c09(%rip),%rcx # 0xc8c43 3a: f7 d8 neg %eax 3c: 64 89 01 mov %eax,%fs:(%rcx) 3f: 48 rex.W Code starting with the faulting instruction =========================================== 0: 48 3d 01 f0 ff ff cmp $0xfffffffffffff001,%rax 6: 73 01 jae 0x9 8: c3 ret 9: 48 8b 0d 09 8c 0c 00 mov 0xc8c09(%rip),%rcx # 0xc8c19 10: f7 d8 neg %eax 12: 64 89 01 mov %eax,%fs:(%rcx) 15: 48 rex.W RSP: 002b:00007ffe2d0ad398 EFLAGS: 00000202 ORIG_RAX: 0000000000000031 RAX: ffffffffffffffda RBX: 00007ffe2d0ad3d0 RCX: 00007f59b934a1e7 RDX: 000000000000001c RSI: 00007ffe2d0ad3d0 RDI: 0000000000000005 RBP: 0000000000000005 R08: 1999999999999999 R09: 0000000000000000 R10: 00007f59b9253298 R11: 0000000000000202 R12: 00007ffe2d0ada61 R13: 0000000000000000 R14: 0000562926516dd8 R15: 00007f59b9479000 </TASK> Fixes: 6fe1e52490a9 ("sctp: check ipv6 addr with sk_bound_dev if set") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Xin Long <lucien.xin@gmail.com> Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> --- net/sctp/ipv6.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-)