kernel/linux.git/net/tipc/socket.c, branch v6.1.168

tipc: fix divide-by-zero in tipc_sk_filter_connect()

2026-03-25T10:03:07+00:00

commit 6c5a9baa15de240e747263aba435a0951da8d8d2 upstream. A user can set conn_timeout to any value via setsockopt(TIPC_CONN_TIMEOUT), including values less than 4. When a SYN is rejected with TIPC_ERR_OVERLOAD and the retry path in tipc_sk_filter_connect() executes: delay %= (tsk->conn_timeout / 4); If conn_timeout is in the range [0, 3], the integer division yields 0, and the modulo operation triggers a divide-by-zero exception, causing a kernel oops/panic. Fix this by clamping conn_timeout to a minimum of 4 at the point of use in tipc_sk_filter_connect(). Oops: divide error: 0000 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 119 Comm: poc-F144 Not tainted 7.0.0-rc2+ RIP: 0010:tipc_sk_filter_rcv (net/tipc/socket.c:2236 net/tipc/socket.c:2362) Call Trace: tipc_sk_backlog_rcv (include/linux/instrumented.h:82 include/linux/atomic/atomic-instrumented.h:32 include/net/sock.h:2357 net/tipc/socket.c:2406) __release_sock (include/net/sock.h:1185 net/core/sock.c:3213) release_sock (net/core/sock.c:3797) tipc_connect (net/tipc/socket.c:2570) __sys_connect (include/linux/file.h:62 include/linux/file.h:83 net/socket.c:2098) Fixes: 6787927475e5 ("tipc: buffer overflow handling in listener socket") Cc: stable@vger.kernel.org Signed-off-by: Mehul Rao Reviewed-by: Tung Nguyen Link: https://patch.msgid.link/20260310170730.28841-1-mehulrao@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

net: deal with most data-races in sk_wait_event()

2023-05-24T16:32:32+00:00

[ Upstream commit d0ac89f6f9879fae316c155de77b5173b3e2c9c9 ] __condition is evaluated twice in sk_wait_event() macro. First invocation is lockless, and reads can race with writes, as spotted by syzbot. BUG: KCSAN: data-race in sk_stream_wait_connect / tcp_disconnect write to 0xffff88812d83d6a0 of 4 bytes by task 9065 on cpu 1: tcp_disconnect+0x2cd/0xdb0 inet_shutdown+0x19e/0x1f0 net/ipv4/af_inet.c:911 __sys_shutdown_sock net/socket.c:2343 [inline] __sys_shutdown net/socket.c:2355 [inline] __do_sys_shutdown net/socket.c:2363 [inline] __se_sys_shutdown+0xf8/0x140 net/socket.c:2361 __x64_sys_shutdown+0x31/0x40 net/socket.c:2361 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd read to 0xffff88812d83d6a0 of 4 bytes by task 9040 on cpu 0: sk_stream_wait_connect+0x1de/0x3a0 net/core/stream.c:75 tcp_sendmsg_locked+0x2e4/0x2120 net/ipv4/tcp.c:1266 tcp_sendmsg+0x30/0x50 net/ipv4/tcp.c:1484 inet6_sendmsg+0x63/0x80 net/ipv6/af_inet6.c:651 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg net/socket.c:747 [inline] __sys_sendto+0x246/0x300 net/socket.c:2142 __do_sys_sendto net/socket.c:2154 [inline] __se_sys_sendto net/socket.c:2150 [inline] __x64_sys_sendto+0x78/0x90 net/socket.c:2150 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd value changed: 0x00000000 -> 0x00000068 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

tipc: fix kernel warning when sending SYN message

2023-02-22T11:59:53+00:00

commit 11a4d6f67cf55883dc78e31c247d1903ed7feccc upstream. When sending a SYN message, this kernel stack trace is observed: ... [ 13.396352] RIP: 0010:_copy_from_iter+0xb4/0x550 ... [ 13.398494] Call Trace: [ 13.398630] [ 13.398630] ? __alloc_skb+0xed/0x1a0 [ 13.398630] tipc_msg_build+0x12c/0x670 [tipc] [ 13.398630] ? shmem_add_to_page_cache.isra.71+0x151/0x290 [ 13.398630] __tipc_sendmsg+0x2d1/0x710 [tipc] [ 13.398630] ? tipc_connect+0x1d9/0x230 [tipc] [ 13.398630] ? __local_bh_enable_ip+0x37/0x80 [ 13.398630] tipc_connect+0x1d9/0x230 [tipc] [ 13.398630] ? __sys_connect+0x9f/0xd0 [ 13.398630] __sys_connect+0x9f/0xd0 [ 13.398630] ? preempt_count_add+0x4d/0xa0 [ 13.398630] ? fpregs_assert_state_consistent+0x22/0x50 [ 13.398630] __x64_sys_connect+0x16/0x20 [ 13.398630] do_syscall_64+0x42/0x90 [ 13.398630] entry_SYSCALL_64_after_hwframe+0x63/0xcd It is because commit a41dad905e5a ("iov_iter: saner checks for attempt to copy to/from iterator") has introduced sanity check for copying from/to iov iterator. Lacking of copy direction from the iterator viewpoint would lead to kernel stack trace like above. This commit fixes this issue by initializing the iov iterator with the correct copy direction when sending SYN or ACK without data. Fixes: f25dcc7687d4 ("tipc: tipc ->sendmsg() conversion") Reported-by: syzbot+d43608d061e8847ec9f3@syzkaller.appspotmail.com Acked-by: Jon Maloy Signed-off-by: Tung Nguyen Link: https://lore.kernel.org/r/20230214012606.5804-1-tung.q.nguyen@dektech.com.au Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

treewide: use prandom_u32_max() when possible, part 1

2022-10-11T23:42:55+00:00

Rather than incurring a division or requesting too many random bytes for the given range, use the prandom_u32_max() function, which only takes the minimum required bytes from the RNG and avoids divisions. This was done mechanically with this coccinelle script: @basic@ expression E; type T; identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; typedef u64; @@ ( - ((T)get_random_u32() % (E)) + prandom_u32_max(E) | - ((T)get_random_u32() & ((E) - 1)) + prandom_u32_max(E * XXX_MAKE_SURE_E_IS_POW2) | - ((u64)(E) * get_random_u32() >> 32) + prandom_u32_max(E) | - ((T)get_random_u32() & ~PAGE_MASK) + prandom_u32_max(PAGE_SIZE) ) @multi_line@ identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; identifier RAND; expression E; @@ - RAND = get_random_u32(); ... when != RAND - RAND %= (E); + RAND = prandom_u32_max(E); // Find a potential literal @literal_mask@ expression LITERAL; type T; identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; position p; @@ ((T)get_random_u32()@p & (LITERAL)) // Add one to the literal. @script:python add_one@ literal << literal_mask.LITERAL; RESULT; @@ value = None if literal.startswith('0x'): value = int(literal, 16) elif literal[0] in '123456789': value = int(literal, 10) if value is None: print("I don't know how to handle %s" % (literal)) cocci.include_match(False) elif value == 2**32 - 1 or value == 2**31 - 1 or value == 2**24 - 1 or value == 2**16 - 1 or value == 2**8 - 1: print("Skipping 0x%x for cleanup elsewhere" % (value)) cocci.include_match(False) elif value & (value + 1) != 0: print("Skipping 0x%x because it's not a power of two minus one" % (value)) cocci.include_match(False) elif literal.startswith('0x'): coccinelle.RESULT = cocci.make_expr("0x%x" % (value + 1)) else: coccinelle.RESULT = cocci.make_expr("%d" % (value + 1)) // Replace the literal mask with the calculated result. @plus_one@ expression literal_mask.LITERAL; position literal_mask.p; expression add_one.RESULT; identifier FUNC; @@ - (FUNC()@p & (LITERAL)) + prandom_u32_max(RESULT) @collapse_ret@ type T; identifier VAR; expression E; @@ { - T VAR; - VAR = (E); - return VAR; + return E; } @drop_var@ type T; identifier VAR; @@ { - T VAR; ... when != VAR } Reviewed-by: Greg Kroah-Hartman Reviewed-by: Kees Cook Reviewed-by: Yury Norov Reviewed-by: KP Singh Reviewed-by: Jan Kara # for ext4 and sbitmap Reviewed-by: Christoph Böhmwalder # for drbd Acked-by: Jakub Kicinski Acked-by: Heiko Carstens # for s390 Acked-by: Ulf Hansson # for mmc Acked-by: Darrick J. Wong # for xfs Signed-off-by: Jason A. Donenfeld

net: Fix data-races around sysctl_[rw]mem(_offset)?.

2022-07-25T11:42:09+00:00

While reading these sysctl variables, they can be changed concurrently. Thus, we need to add READ_ONCE() to their readers. - .sysctl_rmem - .sysctl_rwmem - .sysctl_rmem_offset - .sysctl_wmem_offset - sysctl_tcp_rmem[1, 2] - sysctl_tcp_wmem[1, 2] - sysctl_decnet_rmem[1] - sysctl_decnet_wmem[1] - sysctl_tipc_rmem[1] Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller

net: tipc: fix possible refcount leak in tipc_sk_create()

2022-06-29T12:49:06+00:00

Free sk in case tipc_sk_insert() fails. Signed-off-by: Hangyu Hua Reviewed-by: Tung Nguyen Signed-off-by: David S. Miller

tipc: fix the timer expires after interval 100ms

2022-03-22T09:50:46+00:00

In the timer callback function tipc_sk_timeout(), we're trying to reschedule another timeout to retransmit a setup request if destination link is congested. But we use the incorrect timeout value (msecs_to_jiffies(100)) instead of (jiffies + msecs_to_jiffies(100)), so that the timer expires immediately, it's irrelevant for original description. In this commit we correct the timeout value in sk_reset_timer() Fixes: 6787927475e5 ("tipc: buffer overflow handling in listener socket") Acked-by: Ying Xue Signed-off-by: Hoang Le Link: https://lore.kernel.org/r/20220321042229.314288-1-hoang.h.le@dektech.com.au Signed-off-by: Paolo Abeni

tipc: Fix end of loop tests for list_for_each_entry()

2022-02-23T12:35:40+00:00

These tests are supposed to check if the loop exited via a break or not. However the tests are wrong because if we did not exit via a break then "p" is not a valid pointer. In that case, it's the equivalent of "if (*(u32 *)sr == *last_key) {". That's going to work most of the time, but there is a potential for those to be equal. Fixes: 1593123a6a49 ("tipc: add name table dump to new netlink api") Fixes: 1a1a143daf84 ("tipc: add publication dump to new netlink api") Signed-off-by: Dan Carpenter Signed-off-by: David S. Miller

net ticp:fix a kernel-infoleak in __tipc_sendmsg()

2022-01-01T02:37:08+00:00

struct tipc_socket_addr.ref has a 4-byte hole,and __tipc_getname() currently copying it to user space,causing kernel-infoleak. BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:121 [inline] BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:121 [inline] lib/usercopy.c:33 BUG: KMSAN: kernel-infoleak in _copy_to_user+0x1c9/0x270 lib/usercopy.c:33 lib/usercopy.c:33 instrument_copy_to_user include/linux/instrumented.h:121 [inline] instrument_copy_to_user include/linux/instrumented.h:121 [inline] lib/usercopy.c:33 _copy_to_user+0x1c9/0x270 lib/usercopy.c:33 lib/usercopy.c:33 copy_to_user include/linux/uaccess.h:209 [inline] copy_to_user include/linux/uaccess.h:209 [inline] net/socket.c:287 move_addr_to_user+0x3f6/0x600 net/socket.c:287 net/socket.c:287 __sys_getpeername+0x470/0x6b0 net/socket.c:1987 net/socket.c:1987 __do_sys_getpeername net/socket.c:1997 [inline] __se_sys_getpeername net/socket.c:1994 [inline] __do_sys_getpeername net/socket.c:1997 [inline] net/socket.c:1994 __se_sys_getpeername net/socket.c:1994 [inline] net/socket.c:1994 __x64_sys_getpeername+0xda/0x120 net/socket.c:1994 net/socket.c:1994 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_x64 arch/x86/entry/common.c:51 [inline] arch/x86/entry/common.c:82 do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae Uninit was stored to memory at: tipc_getname+0x575/0x5e0 net/tipc/socket.c:757 net/tipc/socket.c:757 __sys_getpeername+0x3b3/0x6b0 net/socket.c:1984 net/socket.c:1984 __do_sys_getpeername net/socket.c:1997 [inline] __se_sys_getpeername net/socket.c:1994 [inline] __do_sys_getpeername net/socket.c:1997 [inline] net/socket.c:1994 __se_sys_getpeername net/socket.c:1994 [inline] net/socket.c:1994 __x64_sys_getpeername+0xda/0x120 net/socket.c:1994 net/socket.c:1994 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_x64 arch/x86/entry/common.c:51 [inline] arch/x86/entry/common.c:82 do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae Uninit was stored to memory at: msg_set_word net/tipc/msg.h:212 [inline] msg_set_destport net/tipc/msg.h:619 [inline] msg_set_word net/tipc/msg.h:212 [inline] net/tipc/socket.c:1486 msg_set_destport net/tipc/msg.h:619 [inline] net/tipc/socket.c:1486 __tipc_sendmsg+0x44fa/0x5890 net/tipc/socket.c:1486 net/tipc/socket.c:1486 tipc_sendmsg+0xeb/0x140 net/tipc/socket.c:1402 net/tipc/socket.c:1402 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg net/socket.c:724 [inline] sock_sendmsg_nosec net/socket.c:704 [inline] net/socket.c:2409 sock_sendmsg net/socket.c:724 [inline] net/socket.c:2409 ____sys_sendmsg+0xe11/0x12c0 net/socket.c:2409 net/socket.c:2409 ___sys_sendmsg net/socket.c:2463 [inline] ___sys_sendmsg net/socket.c:2463 [inline] net/socket.c:2492 __sys_sendmsg+0x704/0x840 net/socket.c:2492 net/socket.c:2492 __do_sys_sendmsg net/socket.c:2501 [inline] __se_sys_sendmsg net/socket.c:2499 [inline] __do_sys_sendmsg net/socket.c:2501 [inline] net/socket.c:2499 __se_sys_sendmsg net/socket.c:2499 [inline] net/socket.c:2499 __x64_sys_sendmsg+0xe2/0x120 net/socket.c:2499 net/socket.c:2499 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_x64 arch/x86/entry/common.c:51 [inline] arch/x86/entry/common.c:82 do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae Local variable skaddr created at: __tipc_sendmsg+0x2d0/0x5890 net/tipc/socket.c:1419 net/tipc/socket.c:1419 tipc_sendmsg+0xeb/0x140 net/tipc/socket.c:1402 net/tipc/socket.c:1402 Bytes 4-7 of 16 are uninitialized Memory access of size 16 starts at ffff888113753e00 Data copied to user address 0000000020000280 Reported-by: syzbot+cdbd40e0c3ca02cae3b7@syzkaller.appspotmail.com Signed-off-by: Haimin Zhang Acked-by: Jon Maloy Link: https://lore.kernel.org/r/1640918123-14547-1-git-send-email-tcs.kernel@gmail.com Signed-off-by: Jakub Kicinski

tipc: increase timeout in tipc_sk_enqueue()

2021-09-13T11:43:10+00:00

In tipc_sk_enqueue() we use hardcoded 2 jiffies to extract socket buffer from generic queue to particular socket. The 2 jiffies is too short in case there are other high priority tasks get CPU cycles for multiple jiffies update. As result, no buffer could be enqueued to particular socket. To solve this, we switch to use constant timeout 20msecs. Then, the function will be expired between 2 jiffies (CONFIG_100HZ) and 20 jiffies (CONFIG_1000HZ). Fixes: c637c1035534 ("tipc: resolve race problem at unicast message reception") Acked-by: Jon Maloy Signed-off-by: Hoang Le Signed-off-by: David S. Miller