kernel/linux.git/net/sctp/sysctl.c, branch v6.1.168

sctp: add mutual exclusion in proc_sctp_do_udp_port()

2025-05-22T12:10:09+00:00

commit 10206302af856791fbcc27a33ed3c3eb09b2793d upstream. We must serialize calls to sctp_udp_sock_stop() and sctp_udp_sock_start() or risk a crash as syzbot reported: Oops: general protection fault, probably for non-canonical address 0xdffffc000000000d: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000068-0x000000000000006f] CPU: 1 UID: 0 PID: 6551 Comm: syz.1.44 Not tainted 6.14.0-syzkaller-g7f2ff7b62617 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:kernel_sock_shutdown+0x47/0x70 net/socket.c:3653 Call Trace: udp_tunnel_sock_release+0x68/0x80 net/ipv4/udp_tunnel_core.c:181 sctp_udp_sock_stop+0x71/0x160 net/sctp/protocol.c:930 proc_sctp_do_udp_port+0x264/0x450 net/sctp/sysctl.c:553 proc_sys_call_handler+0x3d0/0x5b0 fs/proc/proc_sysctl.c:601 iter_file_splice_write+0x91c/0x1150 fs/splice.c:738 do_splice_from fs/splice.c:935 [inline] direct_splice_actor+0x18f/0x6c0 fs/splice.c:1158 splice_direct_to_actor+0x342/0xa30 fs/splice.c:1102 do_splice_direct_actor fs/splice.c:1201 [inline] do_splice_direct+0x174/0x240 fs/splice.c:1227 do_sendfile+0xafd/0xe50 fs/read_write.c:1368 __do_sys_sendfile64 fs/read_write.c:1429 [inline] __se_sys_sendfile64 fs/read_write.c:1415 [inline] __x64_sys_sendfile64+0x1d8/0x220 fs/read_write.c:1415 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] Fixes: 046c052b475e ("sctp: enable udp tunneling socks") Reported-by: syzbot+fae49d997eb56fa7c74d@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/67ea5c01.050a0220.1547ec.012b.GAE@google.com/T/#u Signed-off-by: Eric Dumazet Cc: Marcelo Ricardo Leitner Acked-by: Xin Long Link: https://patch.msgid.link/20250331091532.224982-1-edumazet@google.com Signed-off-by: Jakub Kicinski [Minor conflict resolved due to code context change.] Signed-off-by: Jianqi Ren Signed-off-by: He Zhe Signed-off-by: Greg Kroah-Hartman

sctp: sysctl: plpmtud_probe_interval: avoid using current->nsproxy

2025-01-17T12:34:42+00:00

commit 6259d2484d0ceff42245d1f09cc8cb6ee72d847a upstream. As mentioned in a previous commit of this series, using the 'net' structure via 'current' is not recommended for different reasons: - Inconsistency: getting info from the reader's/writer's netns vs only from the opener's netns. - current->nsproxy can be NULL in some cases, resulting in an 'Oops' (null-ptr-deref), e.g. when the current task is exiting, as spotted by syzbot [1] using acct(2). The 'net' structure can be obtained from the table->data using container_of(). Note that table->data could also be used directly, as this is the only member needed from the 'net' structure, but that would increase the size of this fix, to use '*data' everywhere 'net->sctp.probe_interval' is used. Fixes: d1e462a7a5f3 ("sctp: add probe_interval in sysctl and sock/asoc/transport") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/67769ecb.050a0220.3a8527.003f.GAE@google.com [1] Suggested-by: Al Viro Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20250108-net-sysctl-current-nsproxy-v1-8-5df34b2083e8@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

sctp: sysctl: udp_port: avoid using current->nsproxy

2025-01-17T12:34:42+00:00

commit c10377bbc1972d858eaf0ab366a311b39f8ef1b6 upstream. As mentioned in a previous commit of this series, using the 'net' structure via 'current' is not recommended for different reasons: - Inconsistency: getting info from the reader's/writer's netns vs only from the opener's netns. - current->nsproxy can be NULL in some cases, resulting in an 'Oops' (null-ptr-deref), e.g. when the current task is exiting, as spotted by syzbot [1] using acct(2). The 'net' structure can be obtained from the table->data using container_of(). Note that table->data could also be used directly, but that would increase the size of this fix, while 'sctp.ctl_sock' still needs to be retrieved from 'net' structure. Fixes: 046c052b475e ("sctp: enable udp tunneling socks") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/67769ecb.050a0220.3a8527.003f.GAE@google.com [1] Suggested-by: Al Viro Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20250108-net-sysctl-current-nsproxy-v1-7-5df34b2083e8@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

sctp: sysctl: auth_enable: avoid using current->nsproxy

2025-01-17T12:34:41+00:00

commit 15649fd5415eda664ef35780c2013adeb5d9c695 upstream. As mentioned in a previous commit of this series, using the 'net' structure via 'current' is not recommended for different reasons: - Inconsistency: getting info from the reader's/writer's netns vs only from the opener's netns. - current->nsproxy can be NULL in some cases, resulting in an 'Oops' (null-ptr-deref), e.g. when the current task is exiting, as spotted by syzbot [1] using acct(2). The 'net' structure can be obtained from the table->data using container_of(). Note that table->data could also be used directly, but that would increase the size of this fix, while 'sctp.ctl_sock' still needs to be retrieved from 'net' structure. Fixes: b14878ccb7fa ("net: sctp: cache auth_enable per endpoint") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/67769ecb.050a0220.3a8527.003f.GAE@google.com [1] Suggested-by: Al Viro Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20250108-net-sysctl-current-nsproxy-v1-6-5df34b2083e8@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

sctp: sysctl: rto_min/max: avoid using current->nsproxy

2025-01-17T12:34:41+00:00

commit 9fc17b76fc70763780aa78b38fcf4742384044a5 upstream. As mentioned in a previous commit of this series, using the 'net' structure via 'current' is not recommended for different reasons: - Inconsistency: getting info from the reader's/writer's netns vs only from the opener's netns. - current->nsproxy can be NULL in some cases, resulting in an 'Oops' (null-ptr-deref), e.g. when the current task is exiting, as spotted by syzbot [1] using acct(2). The 'net' structure can be obtained from the table->data using container_of(). Note that table->data could also be used directly, as this is the only member needed from the 'net' structure, but that would increase the size of this fix, to use '*data' everywhere 'net->sctp.rto_min/max' is used. Fixes: 4f3fdf3bc59c ("sctp: add check rto_min and rto_max in sysctl") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/67769ecb.050a0220.3a8527.003f.GAE@google.com [1] Suggested-by: Al Viro Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20250108-net-sysctl-current-nsproxy-v1-5-5df34b2083e8@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

sctp: sysctl: cookie_hmac_alg: avoid using current->nsproxy

2025-01-17T12:34:41+00:00

commit ea62dd1383913b5999f3d16ae99d411f41b528d4 upstream. As mentioned in a previous commit of this series, using the 'net' structure via 'current' is not recommended for different reasons: - Inconsistency: getting info from the reader's/writer's netns vs only from the opener's netns. - current->nsproxy can be NULL in some cases, resulting in an 'Oops' (null-ptr-deref), e.g. when the current task is exiting, as spotted by syzbot [1] using acct(2). The 'net' structure can be obtained from the table->data using container_of(). Note that table->data could also be used directly, as this is the only member needed from the 'net' structure, but that would increase the size of this fix, to use '*data' everywhere 'net->sctp.sctp_hmac_alg' is used. Fixes: 3c68198e7511 ("sctp: Make hmac algorithm selection for cookie generation dynamic") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/67769ecb.050a0220.3a8527.003f.GAE@google.com [1] Suggested-by: Al Viro Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20250108-net-sysctl-current-nsproxy-v1-4-5df34b2083e8@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

sctp: sysctl: make extra pointers netns aware

2022-12-31T12:32:28+00:00

[ Upstream commit da05cecc4939c0410d56c29e252998b192756318 ] Recently, a customer reported that from their container whose net namespace is different to the host's init_net, they can't set the container's net.sctp.rto_max to any value smaller than init_net.sctp.rto_min. For instance, Host: sudo sysctl net.sctp.rto_min net.sctp.rto_min = 1000 Container: echo 100 > /mnt/proc-net/sctp/rto_min echo 400 > /mnt/proc-net/sctp/rto_max echo: write error: Invalid argument This is caused by the check made from this'commit 4f3fdf3bc59c ("sctp: add check rto_min and rto_max in sysctl")' When validating the input value, it's always referring the boundary value set for the init_net namespace. Having container's rto_max smaller than host's init_net.sctp.rto_min does make sense. Consider that the rto between two containers on the same host is very likely smaller than it for two hosts. So to fix this problem, as suggested by Marcelo, this patch makes the extra pointers of rto_min, rto_max, pf_retrans, and ps_retrans point to the corresponding variables from the newly created net namespace while the new net namespace is being registered in sctp_sysctl_net_register. Fixes: 4f3fdf3bc59c ("sctp: add check rto_min and rto_max in sysctl") Reviewed-by: Marcelo Ricardo Leitner Reviewed-by: Jakub Kicinski Acked-by: Marcelo Ricardo Leitner Signed-off-by: Firo Yang Link: https://lore.kernel.org/r/20221209054854.23889-1-firo.yang@suse.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

sctp: add probe_interval in sysctl and sock/asoc/transport

2021-06-22T18:28:51+00:00

PLPMTUD can be enabled by doing 'sysctl -w net.sctp.probe_interval=n'. 'n' is the interval for PLPMTUD probe timer in milliseconds, and it can't be less than 5000 if it's not 0. All asoc/transport's PLPMTUD in a new socket will be enabled by default. Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller

sctp: fix the proc_handler for sysctl encap_port

2021-05-25T22:18:29+00:00

proc_dointvec() cannot do min and max check for setting a value when extra1/extra2 is set, so change it to proc_dointvec_minmax() for sysctl encap_port. Fixes: e8a3001c2120 ("sctp: add encap_port for netns sock asoc and transport") Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: enable udp tunneling socks

2020-10-30T22:24:49+00:00

This patch is to enable udp tunneling socks by calling sctp_udp_sock_start() in sctp_ctrlsock_init(), and sctp_udp_sock_stop() in sctp_ctrlsock_exit(). Also add sysctl udp_port to allow changing the listening sock's port by users. Wit this patch, the whole sctp over udp feature can be enabled and used. v1->v2: - Also update ctl_sock udp_port in proc_sctp_do_udp_port() where netns udp_port gets changed. v2->v3: - Call htons() when setting sk udp_port from netns udp_port. v3->v4: - Not call sctp_udp_sock_start() when new_value is 0. - Add udp_port entry in ip-sysctl.rst. v4->v5: - Not call sctp_udp_sock_start/stop() in sctp_ctrlsock_init/exit(). - Improve the description of udp_port in ip-sysctl.rst. Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Signed-off-by: Jakub Kicinski