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2021-11-20ipv4: Exposing __ip_sock_set_tos() in ip.hGravatar Poorva Sonparote 1-1/+1
Making the static function __ip_sock_set_tos() from net/ipv4/ip_sockglue.c accessible by declaring it in include/net/ip.h The reason for doing this is to use this function to set IP_TOS value in mptcp_setsockopt() without the lock. Signed-off-by: Poorva Sonparote <psonparo@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-25ipv4: guard IP_MINTTL with a static keyGravatar Eric Dumazet 1-0/+6
RFC 5082 IP_MINTTL option is rarely used on hosts. Add a static key to remove from TCP fast path useless code, and potential cache line miss to fetch inet_sk(sk)->min_ttl Note that once ip4_min_ttl static key has been enabled, it stays enabled until next boot. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-10-25ipv4: annotate data races arount inet->min_ttlGravatar Eric Dumazet 1-1/+4
No report yet from KCSAN, yet worth documenting the races. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-08-05net/ipv4/ipv6: Replace one-element arraya with flexible-array membersGravatar Gustavo A. R. Silva 1-9/+10
There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. Use an anonymous union with a couple of anonymous structs in order to keep userspace unchanged and refactor the related code accordingly: $ pahole -C group_filter net/ipv4/ip_sockglue.o struct group_filter { union { struct { __u32 gf_interface_aux; /* 0 4 */ /* XXX 4 bytes hole, try to pack */ struct __kernel_sockaddr_storage gf_group_aux; /* 8 128 */ /* --- cacheline 2 boundary (128 bytes) was 8 bytes ago --- */ __u32 gf_fmode_aux; /* 136 4 */ __u32 gf_numsrc_aux; /* 140 4 */ struct __kernel_sockaddr_storage gf_slist[1]; /* 144 128 */ }; /* 0 272 */ struct { __u32 gf_interface; /* 0 4 */ /* XXX 4 bytes hole, try to pack */ struct __kernel_sockaddr_storage gf_group; /* 8 128 */ /* --- cacheline 2 boundary (128 bytes) was 8 bytes ago --- */ __u32 gf_fmode; /* 136 4 */ __u32 gf_numsrc; /* 140 4 */ struct __kernel_sockaddr_storage gf_slist_flex[0]; /* 144 0 */ }; /* 0 144 */ }; /* 0 272 */ /* size: 272, cachelines: 5, members: 1 */ /* last cacheline: 16 bytes */ }; $ pahole -C compat_group_filter net/ipv4/ip_sockglue.o struct compat_group_filter { union { struct { __u32 gf_interface_aux; /* 0 4 */ struct __kernel_sockaddr_storage gf_group_aux __attribute__((__aligned__(4))); /* 4 128 */ /* --- cacheline 2 boundary (128 bytes) was 4 bytes ago --- */ __u32 gf_fmode_aux; /* 132 4 */ __u32 gf_numsrc_aux; /* 136 4 */ struct __kernel_sockaddr_storage gf_slist[1] __attribute__((__aligned__(4))); /* 140 128 */ } __attribute__((__packed__)) __attribute__((__aligned__(4))); /* 0 268 */ struct { __u32 gf_interface; /* 0 4 */ struct __kernel_sockaddr_storage gf_group __attribute__((__aligned__(4))); /* 4 128 */ /* --- cacheline 2 boundary (128 bytes) was 4 bytes ago --- */ __u32 gf_fmode; /* 132 4 */ __u32 gf_numsrc; /* 136 4 */ struct __kernel_sockaddr_storage gf_slist_flex[0] __attribute__((__aligned__(4))); /* 140 0 */ } __attribute__((__packed__)) __attribute__((__aligned__(4))); /* 0 140 */ } __attribute__((__aligned__(1))); /* 0 268 */ /* size: 268, cachelines: 5, members: 1 */ /* forced alignments: 1 */ /* last cacheline: 12 bytes */ } __attribute__((__packed__)); This helps with the ongoing efforts to globally enable -Warray-bounds and get us closer to being able to tighten the FORTIFY_SOURCE routines on memcpy(). [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://www.kernel.org/doc/html/v5.10/process/deprecated.html#zero-length-and-one-element-arrays Link: https://github.com/KSPP/linux/issues/79 Link: https://github.com/KSPP/linux/issues/109 Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-05net/ipv4: Revert use of struct_size() helperGravatar Gustavo A. R. Silva 1-7/+5
Revert the use of structr_size() and stay with IP_MSFILTER_SIZE() for now, as in this case, the size of struct ip_msfilter didn't change with the addition of the flexible array imsf_slist_flex[]. So, if we use struct_size() we will be allocating and calculating the size of struct ip_msfilter with one too many items for imsf_slist_flex[]. We might use struct_size() in the future, but for now let's stay with IP_MSFILTER_SIZE(). Fixes: 2d3e5caf96b9 ("net/ipv4: Replace one-element array with flexible-array member") Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-02net/ipv4: Replace one-element array with flexible-array memberGravatar Gustavo A. R. Silva 1-7/+8
There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. Use an anonymous union with a couple of anonymous structs in order to keep userspace unchanged: $ pahole -C ip_msfilter net/ipv4/ip_sockglue.o struct ip_msfilter { union { struct { __be32 imsf_multiaddr_aux; /* 0 4 */ __be32 imsf_interface_aux; /* 4 4 */ __u32 imsf_fmode_aux; /* 8 4 */ __u32 imsf_numsrc_aux; /* 12 4 */ __be32 imsf_slist[1]; /* 16 4 */ }; /* 0 20 */ struct { __be32 imsf_multiaddr; /* 0 4 */ __be32 imsf_interface; /* 4 4 */ __u32 imsf_fmode; /* 8 4 */ __u32 imsf_numsrc; /* 12 4 */ __be32 imsf_slist_flex[0]; /* 16 0 */ }; /* 0 16 */ }; /* 0 20 */ /* size: 20, cachelines: 1, members: 1 */ /* last cacheline: 20 bytes */ }; Also, refactor the code accordingly and make use of the struct_size() and flex_array_size() helpers. This helps with the ongoing efforts to globally enable -Warray-bounds and get us closer to being able to tighten the FORTIFY_SOURCE routines on memcpy(). [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://www.kernel.org/doc/html/v5.10/process/deprecated.html#zero-length-and-one-element-arrays Link: https://github.com/KSPP/linux/issues/79 Link: https://github.com/KSPP/linux/issues/109 Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-25net: Remove duplicated midx check against 0Gravatar Miaohe Lin 1-3/+2
Check midx against 0 is always equal to check midx against sk_bound_dev_if when sk_bound_dev_if is known not equal to 0 in these case. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-24icmp: prepare rfc 4884 for ipv6Gravatar Willem de Bruijn 1-1/+13
The RFC 4884 spec is largely the same between IPv4 and IPv6. Factor out the IPv4 specific parts in preparation for IPv6 support: - icmp types supported - icmp header size, and thus offset to original datagram start - datagram length field offset in icmp(6)hdr. - datagram length field word size: 4B for IPv4, 8B for IPv6. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-24net: pass a sockptr_t into ->setsockoptGravatar Christoph Hellwig 1-8/+5
Rework the remaining setsockopt code to pass a sockptr_t instead of a plain user pointer. This removes the last remaining set_fs(KERNEL_DS) outside of architecture specific code. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Stefan Schmidt <stefan@datenfreihafen.org> [ieee802154] Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-24net/ipv4: switch do_ip_setsockopt to sockptr_tGravatar Christoph Hellwig 1-35/+33
Pass a sockptr_t to prepare for set_fs-less handling of the kernel pointer from bpf-cgroup. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-24net/ipv4: merge ip_options_get and ip_options_get_from_userGravatar Christoph Hellwig 1-3/+4
Use the sockptr_t type to merge the versions. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-24net/ipv4: switch ip_mroute_setsockopt to sockptr_tGravatar Christoph Hellwig 1-1/+2
Pass a sockptr_t to prepare for set_fs-less handling of the kernel pointer from bpf-cgroup. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-24bpfilter: switch bpfilter_ip_set_sockopt to sockptr_tGravatar Christoph Hellwig 1-1/+2
This is mostly to prepare for cleaning up the callers, as bpfilter by design can't handle kernel pointers. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-24netfilter: switch nf_setsockopt to sockptr_tGravatar Christoph Hellwig 1-1/+2
Pass a sockptr_t to prepare for set_fs-less handling of the kernel pointer from bpf-cgroup. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-24net/xfrm: switch xfrm_user_policy to sockptr_tGravatar Christoph Hellwig 1-1/+2
Pass a sockptr_t to prepare for set_fs-less handling of the kernel pointer from bpf-cgroup. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19icmp: support rfc 4884Gravatar Willem de Bruijn 1-0/+12
Add setsockopt SOL_IP/IP_RECVERR_4884 to return the offset to an extension struct if present. ICMP messages may include an extension structure after the original datagram. RFC 4884 standardized this behavior. It stores the offset in words to the extension header in u8 icmphdr.un.reserved[1]. The field is valid only for ICMP types destination unreachable, time exceeded and parameter problem, if length is at least 128 bytes and entire packet does not exceed 576 bytes. Return the offset to the start of the extension struct when reading an ICMP error from the error queue, if it matches the above constraints. Do not return the raw u8 field. Return the offset from the start of the user buffer, in bytes. The kernel does not return the network and transport headers, so subtract those. Also validate the headers. Return the offset regardless of validation, as an invalid extension must still not be misinterpreted as part of the original datagram. Note that !invalid does not imply valid. If the extension version does not match, no validation can take place, for instance. For backward compatibility, make this optional, set by setsockopt SOL_IP/IP_RECVERR_RFC4884. For API example and feature test, see github.com/wdebruij/kerneltools/blob/master/tests/recv_icmp_v2.c For forward compatibility, reserve only setsockopt value 1, leaving other bits for additional icmp extensions. Changes v1->v2: - convert word offset to byte offset from start of user buffer - return in ee_data as u8 may be insufficient - define extension struct and object header structs - return len only if constraints met - if returning len, also validate Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19net/ipv4: remove compat_ip_{get,set}sockoptGravatar Christoph Hellwig 1-153/+61
Handle the few cases that need special treatment in-line using in_compat_syscall(). Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19net/ipv4: factor out mcast join/leave setsockopt helpersGravatar Christoph Hellwig 1-53/+56
Factor out one helper each for setting the native and compat version of the MCAST_MSFILTER option. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19net/ipv4: factor out MCAST_MSFILTER setsockopt helpersGravatar Christoph Hellwig 1-76/+86
Factor out one helper each for setting the native and compat version of the MCAST_MSFILTER option. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19net/ipv4: factor out MCAST_MSFILTER getsockopt helpersGravatar Christoph Hellwig 1-61/+70
Factor out one helper each for getting the native and compat version of the MCAST_MSFILTER option. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19netfilter: remove the compat_{get,set} methodsGravatar Christoph Hellwig 1-3/+2
All instances handle compat sockopts via in_compat_syscall() now, so remove the compat_{get,set} methods as well as the compat_nf_{get,set}sockopt wrappers. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-28ipv4: add ip_sock_set_pktinfoGravatar Christoph Hellwig 1-0/+8
Add a helper to directly set the IP_PKTINFO sockopt from kernel space without going through a fake uaccess. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-28ipv4: add ip_sock_set_mtu_discoverGravatar Christoph Hellwig 1-0/+11
Add a helper to directly set the IP_MTU_DISCOVER sockopt from kernel space without going through a fake uaccess. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Howells <dhowells@redhat.com> [rxrpc bits] Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-28ipv4: add ip_sock_set_recverrGravatar Christoph Hellwig 1-0/+8
Add a helper to directly set the IP_RECVERR sockopt from kernel space without going through a fake uaccess. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-28ipv4: add ip_sock_set_freebindGravatar Christoph Hellwig 1-0/+8
Add a helper to directly set the IP_FREEBIND sockopt from kernel space without going through a fake uaccess. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-28ipv4: add ip_sock_set_tosGravatar Christoph Hellwig 1-9/+21
Add a helper to directly set the IP_TOS sockopt from kernel space without going through a fake uaccess. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-25ipv4: potential underflow in compat_ip_setsockopt()Gravatar Dan Carpenter 1-1/+1
The value of "n" is capped at 0x1ffffff but it checked for negative values. I don't think this causes a problem but I'm not certain and it's harmless to prevent it. Fixes: 2e04172875c9 ("ipv4: do compat setsockopt for MCAST_MSFILTER directly") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-20handle the group_source_req options directlyGravatar Al Viro 1-2/+21
Native ->setsockopt() handling of these options (MCAST_..._SOURCE_GROUP and MCAST_{,UN}BLOCK_SOURCE) consists of copyin + call of a helper that does the actual work. The only change needed for ->compat_setsockopt() is a slightly different copyin - the helpers can be reused as-is. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-05-20ipv4: take handling of group_source_req options into a helperGravatar Al Viro 1-39/+44
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-05-20ipv[46]: do compat setsockopt for MCAST_{JOIN,LEAVE}_GROUP directlyGravatar Al Viro 1-0/+31
direct parallel to the way these two are handled in the native ->setsockopt() instances - the helpers that do the real work are already separated and can be reused as-is in this case. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-05-20ipv4: do compat setsockopt for MCAST_MSFILTER directlyGravatar Al Viro 1-1/+47
Parallel to what the native setsockopt() does, except that unlike the native setsockopt() we do not use memdup_user() - we want the sockaddr_storage fields properly aligned, so we allocate 4 bytes more and copy compat_group_filter at the offset 4, which yields the proper alignments. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-05-20set_mcast_msfilter(): take the guts of setsockopt(MCAST_MSFILTER) into a helperGravatar Al Viro 1-33/+40
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-05-20get rid of compat_mc_getsockopt()Gravatar Al Viro 1-3/+41
now we can do MCAST_MSFILTER in compat ->getsockopt() without playing silly buggers with copying things back and forth. We can form a native struct group_filter (sans the variable-length tail) on stack, pass that + pointer to the tail of original request to the helper doing the bulk of the work, then do the rest of copyout - same as the native getsockopt() does. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-05-20ip*_mc_gsfget(): lift copyout of struct group_filter into callersGravatar Al Viro 1-5/+14
pass the userland pointer to the array in its tail, so that part gets copied out by our functions; copyout of everything else is done in the callers. Rationale: reuse for compat; the array is the same in native and compat, the layout of parts before it is different for compat. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-05-20compat_ip{,v6}_setsockopt(): enumerate MCAST_... options explicitlyGravatar Al Viro 1-1/+9
We want to check if optname is among the MCAST_... ones; do that as an explicit switch. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-05-11net: cleanly handle kernel vs user buffers for ->msg_controlGravatar Christoph Hellwig 1-1/+2
The msg_control field in struct msghdr can either contain a user pointer when used with the recvmsg system call, or a kernel pointer when used with sendmsg. To complicate things further kernel_recvmsg can stuff a kernel pointer in and then use set_fs to make the uaccess helpers accept it. Replace it with a union of a kernel pointer msg_control field, and a user pointer msg_control_user one, and allow kernel_recvmsg operate on a proper kernel pointer using a bitfield to override the normal choice of a user pointer for recvmsg. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-25ip_sockglue: Fix missing-check bug in ip_ra_control()Gravatar Gen Zhang 1-0/+2
In function ip_ra_control(), the pointer new_ra is allocated a memory space via kmalloc(). And it is used in the following codes. However, when there is a memory allocation error, kmalloc() fails. Thus null pointer dereference may happen. And it will cause the kernel to crash. Therefore, we should check the return value and handle the error. Signed-off-by: Gen Zhang <blackgod016574@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-10ip: on queued skb use skb_header_pointer instead of pskb_may_pullGravatar Willem de Bruijn 1-7/+5
Commit 2efd4fca703a ("ip: in cmsg IP(V6)_ORIGDSTADDR call pskb_may_pull") avoided a read beyond the end of the skb linear segment by calling pskb_may_pull. That function can trigger a BUG_ON in pskb_expand_head if the skb is shared, which it is when when peeking. It can also return ENOMEM. Avoid both by switching to safer skb_header_pointer. Fixes: 2efd4fca703a ("ip: in cmsg IP(V6)_ORIGDSTADDR call pskb_may_pull") Reported-by: syzbot <syzkaller@googlegroups.com> Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-05net: bpfilter: fix iptables failure if bpfilter_umh is disabledGravatar Taehee Yoo 1-3/+3
When iptables command is executed, ip_{set/get}sockopt() try to upload bpfilter.ko if bpfilter is enabled. if it couldn't find bpfilter.ko, command is failed. bpfilter.ko is generated if CONFIG_BPFILTER_UMH is enabled. ip_{set/get}sockopt() only checks CONFIG_BPFILTER. So that if CONFIG_BPFILTER is enabled and CONFIG_BPFILTER_UMH is disabled, iptables command is always failed. test config: CONFIG_BPFILTER=y # CONFIG_BPFILTER_UMH is not set test command: %iptables -L iptables: No chain/target/match by that name. Fixes: d2ba09c17a06 ("net: add skeleton of bpfilter kernel module") Signed-off-by: Taehee Yoo <ap420073@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-02ipv4: fix use-after-free in ip_cmsg_recv_dstaddr()Gravatar Eric Dumazet 1-2/+1
Caching ip_hdr(skb) before a call to pskb_may_pull() is buggy, do not do it. Fixes: 2efd4fca703a ("ip: in cmsg IP(V6)_ORIGDSTADDR call pskb_may_pull") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Willem de Bruijn <willemb@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-24ip: in cmsg IP(V6)_ORIGDSTADDR call pskb_may_pullGravatar Willem de Bruijn 1-2/+5
Syzbot reported a read beyond the end of the skb head when returning IPV6_ORIGDSTADDR: BUG: KMSAN: kernel-infoleak in put_cmsg+0x5ef/0x860 net/core/scm.c:242 CPU: 0 PID: 4501 Comm: syz-executor128 Not tainted 4.17.0+ #9 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x185/0x1d0 lib/dump_stack.c:113 kmsan_report+0x188/0x2a0 mm/kmsan/kmsan.c:1125 kmsan_internal_check_memory+0x138/0x1f0 mm/kmsan/kmsan.c:1219 kmsan_copy_to_user+0x7a/0x160 mm/kmsan/kmsan.c:1261 copy_to_user include/linux/uaccess.h:184 [inline] put_cmsg+0x5ef/0x860 net/core/scm.c:242 ip6_datagram_recv_specific_ctl+0x1cf3/0x1eb0 net/ipv6/datagram.c:719 ip6_datagram_recv_ctl+0x41c/0x450 net/ipv6/datagram.c:733 rawv6_recvmsg+0x10fb/0x1460 net/ipv6/raw.c:521 [..] This logic and its ipv4 counterpart read the destination port from the packet at skb_transport_offset(skb) + 4. With MSG_MORE and a local SOCK_RAW sender, syzbot was able to cook a packet that stores headers exactly up to skb_transport_offset(skb) in the head and the remainder in a frag. Call pskb_may_pull before accessing the pointer to ensure that it lies in skb head. Link: http://lkml.kernel.org/r/CAF=yD-LEJwZj5a1-bAAj2Oy_hKmGygV6rsJ_WOrAYnv-fnayiQ@mail.gmail.com Reported-by: syzbot+9adb4b567003cac781f0@syzkaller.appspotmail.com Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-16ipv4/igmp: init group mode as INCLUDE when join source groupGravatar Hangbin Liu 1-2/+2
Based on RFC3376 5.1 If no interface state existed for that multicast address before the change (i.e., the change consisted of creating a new per-interface record), or if no state exists after the change (i.e., the change consisted of deleting a per-interface record), then the "non-existent" state is considered to have a filter mode of INCLUDE and an empty source list. Which means a new multicast group should start with state IN(). Function ip_mc_join_group() works correctly for IGMP ASM(Any-Source Multicast) mode. It adds a group with state EX() and inits crcount to mc_qrv, so the kernel will send a TO_EX() report message after adding group. But for IGMPv3 SSM(Source-specific multicast) JOIN_SOURCE_GROUP mode, we split the group joining into two steps. First we join the group like ASM, i.e. via ip_mc_join_group(). So the state changes from IN() to EX(). Then we add the source-specific address with INCLUDE mode. So the state changes from EX() to IN(A). Before the first step sends a group change record, we finished the second step. So we will only send the second change record. i.e. TO_IN(A). Regarding the RFC stands, we should actually send an ALLOW(A) message for SSM JOIN_SOURCE_GROUP as the state should mimic the 'IN() to IN(A)' transition. The issue was exposed by commit a052517a8ff65 ("net/multicast: should not send source list records when have filter mode change"). Before this change, we used to send both ALLOW(A) and TO_IN(A). After this change we only send TO_IN(A). Fix it by adding a new parameter to init group mode. Also add new wrapper functions so we don't need to change too much code. v1 -> v2: In my first version I only cleared the group change record. But this is not enough. Because when a new group join, it will init as EXCLUDE and trigger an filter mode change in ip/ip6_mc_add_src(), which will clear all source addresses' sf_crcount. This will prevent early joined address sending state change records if multi source addressed joined at the same time. In v2 patch, I fixed it by directly initializing the mode to INCLUDE for SSM JOIN_SOURCE_GROUP. I also split the original patch into two separated patches for IPv4 and IPv6. Fixes: a052517a8ff65 ("net/multicast: should not send source list records when have filter mode change") Reviewed-by: Stefano Brivio <sbrivio@redhat.com> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-26Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netGravatar David S. Miller 1-2/+0
Lots of easy overlapping changes in the confict resolutions here. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-24ipv4: remove warning in ip_recv_errorGravatar Willem de Bruijn 1-2/+0
A precondition check in ip_recv_error triggered on an otherwise benign race. Remove the warning. The warning triggers when passing an ipv6 socket to this ipv4 error handling function. RaceFuzzer was able to trigger it due to a race in setsockopt IPV6_ADDRFORM. --- CPU0 do_ipv6_setsockopt sk->sk_socket->ops = &inet_dgram_ops; --- CPU1 sk->sk_prot->recvmsg udp_recvmsg ip_recv_error WARN_ON_ONCE(sk->sk_family == AF_INET6); --- CPU0 do_ipv6_setsockopt sk->sk_family = PF_INET; This socket option converts a v6 socket that is connected to a v4 peer to an v4 socket. It updates the socket on the fly, changing fields in sk as well as other structs. This is inherently non-atomic. It races with the lockless udp_recvmsg path. No other code makes an assumption that these fields are updated atomically. It is benign here, too, as ip_recv_error cares only about the protocol of the skbs enqueued on the error queue, for which sk_family is not a precise predictor (thanks to another isue with IPV6_ADDRFORM). Link: http://lkml.kernel.org/r/20180518120826.GA19515@dragonet.kaist.ac.kr Fixes: 7ce875e5ecb8 ("ipv4: warn once on passing AF_INET6 socket to ip_recv_error") Reported-by: DaeRyong Jeong <threeearcat@gmail.com> Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-23net: add skeleton of bpfilter kernel moduleGravatar Alexei Starovoitov 1-0/+17
bpfilter.ko consists of bpfilter_kern.c (normal kernel module code) and user mode helper code that is embedded into bpfilter.ko The steps to build bpfilter.ko are the following: - main.c is compiled by HOSTCC into the bpfilter_umh elf executable file - with quite a bit of objcopy and Makefile magic the bpfilter_umh elf file is converted into bpfilter_umh.o object file with _binary_net_bpfilter_bpfilter_umh_start and _end symbols Example: $ nm ./bld_x64/net/bpfilter/bpfilter_umh.o 0000000000004cf8 T _binary_net_bpfilter_bpfilter_umh_end 0000000000004cf8 A _binary_net_bpfilter_bpfilter_umh_size 0000000000000000 T _binary_net_bpfilter_bpfilter_umh_start - bpfilter_umh.o and bpfilter_kern.o are linked together into bpfilter.ko bpfilter_kern.c is a normal kernel module code that calls the fork_usermode_blob() helper to execute part of its own data as a user mode process. Notice that _binary_net_bpfilter_bpfilter_umh_start - end is placed into .init.rodata section, so it's freed as soon as __init function of bpfilter.ko is finished. As part of __init the bpfilter.ko does first request/reply action via two unix pipe provided by fork_usermode_blob() helper to make sure that umh is healthy. If not it will kill it via pid. Later bpfilter_process_sockopt() will be called from bpfilter hooks in get/setsockopt() to pass iptable commands into umh via bpfilter.ko If admin does 'rmmod bpfilter' the __exit code bpfilter.ko will kill umh as well. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-22net: Replace ip_ra_lock with per-net mutexGravatar Kirill Tkhai 1-9/+6
Since ra_chain is per-net, we may use per-net mutexes to protect them in ip_ra_control(). This improves scalability. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-22net: Make ip_ra_chain per struct netGravatar Kirill Tkhai 1-13/+2
This is optimization, which makes ip_call_ra_chain() iterate less sockets to find the sockets it's looking for. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-22net: Revert "ipv4: fix a deadlock in ip_ra_control"Gravatar Kirill Tkhai 1-1/+0
This reverts commit 1215e51edad1. Since raw_close() is used on every RAW socket destruction, the changes made by 1215e51edad1 scale sadly. This clearly seen on endless unshare(CLONE_NEWNET) test, and cleanup_net() kwork spends a lot of time waiting for rtnl_lock() introduced by this commit. Previous patch moved IP_ROUTER_ALERT out of rtnl_lock(), so we revert this patch. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-22net: Move IP_ROUTER_ALERT out of lock_sock(sk)Gravatar Kirill Tkhai 1-3/+2
ip_ra_control() does not need sk_lock. Who are the another users of ip_ra_chain? ip_mroute_setsockopt() doesn't take sk_lock, while parallel IP_ROUTER_ALERT syscalls are synchronized by ip_ra_lock. So, we may move this command out of sk_lock. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-22net: Revert "ipv4: get rid of ip_ra_lock"Gravatar Kirill Tkhai 1-2/+10
This reverts commit ba3f571d5dde. The commit was made after 1215e51edad1 "ipv4: fix a deadlock in ip_ra_control", and killed ip_ra_lock, which became useless after rtnl_lock() made used to destroy every raw ipv4 socket. This scales very bad, and next patch in series reverts 1215e51edad1. ip_ra_lock will be used again. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>