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2018-04-12strparser: Fix incorrect strp->need_bytes value.Doron Roberts-Kedes1-4/+3
strp_data_ready resets strp->need_bytes to 0 if strp_peek_len indicates that the remainder of the message has been received. However, do_strp_work does not reset strp->need_bytes to 0. If do_strp_work completes a partial message, the value of strp->need_bytes will continue to reflect the needed bytes of the previous message, causing future invocations of strp_data_ready to return early if strp->need_bytes is less than strp_peek_len. Resetting strp->need_bytes to 0 in __strp_recv on handing a full message to the upper layer solves this problem. __strp_recv also calculates strp->need_bytes using stm->accum_len before stm->accum_len has been incremented by cand_len. This can cause strp->need_bytes to be equal to the full length of the message instead of the full length minus the accumulated length. This, in turn, causes strp_data_ready to return early, even when there is sufficient data to complete the partial message. Incrementing stm->accum_len before using it to calculate strp->need_bytes solves this problem. Found while testing net/tls_sw recv path. Fixes: 43a0c6751a322847 ("strparser: Stream parser for messages") Signed-off-by: Doron Roberts-Kedes <doronrk@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-27strparser: Fix sign of err codesDave Watson1-2/+2
strp_parser_err is called with a negative code everywhere, which then calls abort_parser with a negative code. strp_msg_timeout calls abort_parser directly with a positive code. Negate ETIMEDOUT to match signed-ness of other calls. The default abort_parser callback, strp_abort_strp, sets sk->sk_err to err. Also negate the error here so sk_err always holds a positive value, as the rest of the net code expects. Currently a negative sk_err can result in endless loops, or user code that thinks it actually sent/received err bytes. Found while testing net/tls_sw recv path. Fixes: 43a0c6751a322847 ("strparser: Stream parser for messages") Signed-off-by: Dave Watson <davejwatson@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-28strparser: Call sock_owned_by_user_nocheckTom Herbert1-1/+1
strparser wants to check socket ownership without producing any warnings. As indicated by the comment in the code, it is permissible for owned_by_user to return true. Fixes: 43a0c6751a322847 ("strparser: Stream parser for messages") Reported-by: syzbot <syzkaller@googlegroups.com> Reported-and-tested-by: <syzbot+c91c53af67f9ebe599a337d2e70950366153b295@syzkaller.appspotmail.com> Signed-off-by: Tom Herbert <tom@quantonium.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-25strparser: Use delayed work instead of timer for msg timeoutTom Herbert1-9/+8
Sock lock may be taken in the message timer function which is a problem since timers run in BH. Instead of timers use delayed_work. Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Fixes: bbb03029a899 ("strparser: Generalize strparser") Signed-off-by: Tom Herbert <tom@quantonium.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-24strparser: initialize all callbacksEric Biggers1-1/+1
commit bbb03029a899 ("strparser: Generalize strparser") added more function pointers to 'struct strp_callbacks'; however, kcm_attach() was not updated to initialize them. This could cause the ->lock() and/or ->unlock() function pointers to be set to garbage values, causing a crash in strp_work(). Fix the bug by moving the callback structs into static memory, so unspecified members are zeroed. Also constify them while we're at it. This bug was found by syzkaller, which encountered the following splat: IP: 0x55 PGD 3b1ca067 P4D 3b1ca067 PUD 3b12f067 PMD 0 Oops: 0010 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 2 PID: 1194 Comm: kworker/u8:1 Not tainted 4.13.0-rc4-next-20170811 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Workqueue: kstrp strp_work task: ffff88006bb0e480 task.stack: ffff88006bb10000 RIP: 0010:0x55 RSP: 0018:ffff88006bb17540 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: ffff88006ce4bd60 RCX: 0000000000000000 RDX: 1ffff1000d9c97bd RSI: 0000000000000000 RDI: ffff88006ce4bc48 RBP: ffff88006bb17558 R08: ffffffff81467ab2 R09: 0000000000000000 R10: ffff88006bb17438 R11: ffff88006bb17940 R12: ffff88006ce4bc48 R13: ffff88003c683018 R14: ffff88006bb17980 R15: ffff88003c683000 FS: 0000000000000000(0000) GS:ffff88006de00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000055 CR3: 000000003c145000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: process_one_work+0xbf3/0x1bc0 kernel/workqueue.c:2098 worker_thread+0x223/0x1860 kernel/workqueue.c:2233 kthread+0x35e/0x430 kernel/kthread.c:231 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 Code: Bad RIP value. RIP: 0x55 RSP: ffff88006bb17540 CR2: 0000000000000055 ---[ end trace f0e4920047069cee ]--- Here is a C reproducer (requires CONFIG_BPF_SYSCALL=y and CONFIG_AF_KCM=y): #include <linux/bpf.h> #include <linux/kcm.h> #include <linux/types.h> #include <stdint.h> #include <sys/ioctl.h> #include <sys/socket.h> #include <sys/syscall.h> #include <unistd.h> static const struct bpf_insn bpf_insns[3] = { { .code = 0xb7 }, /* BPF_MOV64_IMM(0, 0) */ { .code = 0x95 }, /* BPF_EXIT_INSN() */ }; static const union bpf_attr bpf_attr = { .prog_type = 1, .insn_cnt = 2, .insns = (uintptr_t)&bpf_insns, .license = (uintptr_t)"", }; int main(void) { int bpf_fd = syscall(__NR_bpf, BPF_PROG_LOAD, &bpf_attr, sizeof(bpf_attr)); int inet_fd = socket(AF_INET, SOCK_STREAM, 0); int kcm_fd = socket(AF_KCM, SOCK_DGRAM, 0); ioctl(kcm_fd, SIOCKCMATTACH, &(struct kcm_attach) { .fd = inet_fd, .bpf_fd = bpf_fd }); } Fixes: bbb03029a899 ("strparser: Generalize strparser") Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Tom Herbert <tom@quantonium.net> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-16net: early init support for strparserJohn Fastabend1-6/+4
It is useful to allow strparser to init sockets before the read_sock callback has been established. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-01strparser: Generalize strparserTom Herbert1-126/+187
Generalize strparser from more than just being used in conjunction with read_sock. strparser will also be used in the send path with zero proxy. The primary change is to create strp_process function that performs the critical processing on skbs. The documentation is also updated to reflect the new uses. Signed-off-by: Tom Herbert <tom@quantonium.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-03strparser: destroy workqueue on module exitWANG Cong1-0/+1
Fixes: 43a0c6751a32 ("strparser: Stream parser for messages") Cc: Tom Herbert <tom@herbertland.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-12strparser: Propagate correct error code in strp_recv()Geert Uytterhoeven1-1/+1
With m68k-linux-gnu-gcc-4.1: net/strparser/strparser.c: In function ‘strp_recv’: net/strparser/strparser.c:98: warning: ‘err’ may be used uninitialized in this function Pass "len" (which is an error code when negative) instead of the uninitialized "err" variable to fix this. Fixes: 43a0c6751a322847 ("strparser: Stream parser for messages") Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-28kcm: Remove TCP specific references from kcm and strparserTom Herbert1-19/+29
kcm and strparser need to work with any type of stream socket not just TCP. Eliminate references to TCP and call generic proto_ops functions of read_sock and peek_len. Also in strp_init check if the socket support the proto_ops read_sock and peek_len. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-23strparser: Queue work when being unpausedTom Herbert1-0/+11
When the upper layer unpauses a stream parser connection we need to queue rx_work to make sure no events are missed. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-22net: strparser: fix strparser sk_user_data checkDave Watson1-3/+0
sk_user_data mismatch between what kcm expects (psock) and what strparser expects (strparser). Queued rx_work, for example calling strp_check_rcv after socket buffer changes, will never complete. sk_user_data is unused in strparser, so just remove the check. Signed-off-by: Dave Watson <davejwatson@fb.com> Acked-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-17strparser: Stream parser for messagesTom Herbert3-0/+497
This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>