linux/net/tipc, branch v6.2

tipc: fix kernel warning when sending SYN message

2023-02-15T04:46:24Z

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

tipc: fix unexpected link reset due to discovery messages

2023-01-06T12:53:10Z

This unexpected behavior is observed: node 1 | node 2 ------ | ------ link is established | link is established reboot | link is reset up | send discovery message receive discovery message | link is established | link is established send discovery message | | receive discovery message | link is reset (unexpected) | send reset message link is reset | It is due to delayed re-discovery as described in function tipc_node_check_dest(): "this link endpoint has already reset and re-established contact with the peer, before receiving a discovery message from that node." However, commit 598411d70f85 has changed the condition for calling tipc_node_link_down() which was the acceptance of new media address. This commit fixes this by restoring the old and correct behavior. Fixes: 598411d70f85 ("tipc: make resetting of links non-atomic") Acked-by: Jon Maloy Signed-off-by: Tung Nguyen Signed-off-by: David S. Miller

treewide: Convert del_timer() to timer_shutdown()

2022-12-25T21:38:09Z

Due to several bugs caused by timers being re-armed after they are shutdown and just before they are freed, a new state of timers was added called "shutdown". After a timer is set to this state, then it can no longer be re-armed. The following script was run to find all the trivial locations where del_timer() or del_timer_sync() is called in the same function that the object holding the timer is freed. It also ignores any locations where the timer->function is modified between the del_timer*() and the free(), as that is not considered a "trivial" case. This was created by using a coccinelle script and the following commands: $ cat timer.cocci @@ expression ptr, slab; identifier timer, rfield; @@ ( - del_timer(&ptr->timer); + timer_shutdown(&ptr->timer); | - del_timer_sync(&ptr->timer); + timer_shutdown_sync(&ptr->timer); ) ... when strict when != ptr->timer ( kfree_rcu(ptr, rfield); | kmem_cache_free(slab, ptr); | kfree(ptr); ) $ spatch timer.cocci . > /tmp/t.patch $ patch -p1 < /tmp/t.patch Link: https://lore.kernel.org/lkml/20221123201306.823305113@linutronix.de/ Signed-off-by: Steven Rostedt (Google) Acked-by: Pavel Machek [ LED ] Acked-by: Kalle Valo [ wireless ] Acked-by: Paolo Abeni [ networking ] Signed-off-by: Linus Torvalds

Merge tag 'pull-iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2022-12-13T02:29:54Z

Pull iov_iter updates from Al Viro: "iov_iter work; most of that is about getting rid of direction misannotations and (hopefully) preventing more of the same for the future" * tag 'pull-iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: use less confusing names for iov_iter direction initializers iov_iter: saner checks for attempt to copy to/from iterator [xen] fix "direction" argument of iov_iter_kvec() [vhost] fix 'direction' argument of iov_iter_{init,bvec}() [target] fix iov_iter_bvec() "direction" argument [s390] memcpy_real(): WRITE is "data source", not destination... [s390] zcore: WRITE is "data source", not destination... [infiniband] READ is "data destination", not source... [fsi] WRITE is "data source", not destination... [s390] copy_oldmem_kernel() - WRITE is "data source", not destination csum_and_copy_to_iter(): handle ITER_DISCARD get rid of unlikely() on page_copy_sane() calls

Merge tag 'random-6.2-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random

2022-12-13T00:22:22Z

Pull random number generator updates from Jason Donenfeld: - Replace prandom_u32_max() and various open-coded variants of it, there is now a new family of functions that uses fast rejection sampling to choose properly uniformly random numbers within an interval: get_random_u32_below(ceil) - [0, ceil) get_random_u32_above(floor) - (floor, U32_MAX] get_random_u32_inclusive(floor, ceil) - [floor, ceil] Coccinelle was used to convert all current users of prandom_u32_max(), as well as many open-coded patterns, resulting in improvements throughout the tree. I'll have a "late" 6.1-rc1 pull for you that removes the now unused prandom_u32_max() function, just in case any other trees add a new use case of it that needs to converted. According to linux-next, there may be two trivial cases of prandom_u32_max() reintroductions that are fixable with a 's/.../.../'. So I'll have for you a final conversion patch doing that alongside the removal patch during the second week. This is a treewide change that touches many files throughout. - More consistent use of get_random_canary(). - Updates to comments, documentation, tests, headers, and simplification in configuration. - The arch_get_random*_early() abstraction was only used by arm64 and wasn't entirely useful, so this has been replaced by code that works in all relevant contexts. - The kernel will use and manage random seeds in non-volatile EFI variables, refreshing a variable with a fresh seed when the RNG is initialized. The RNG GUID namespace is then hidden from efivarfs to prevent accidental leakage. These changes are split into random.c infrastructure code used in the EFI subsystem, in this pull request, and related support inside of EFISTUB, in Ard's EFI tree. These are co-dependent for full functionality, but the order of merging doesn't matter. - Part of the infrastructure added for the EFI support is also used for an improvement to the way vsprintf initializes its siphash key, replacing an sleep loop wart. - The hardware RNG framework now always calls its correct random.c input function, add_hwgenerator_randomness(), rather than sometimes going through helpers better suited for other cases. - The add_latent_entropy() function has long been called from the fork handler, but is a no-op when the latent entropy gcc plugin isn't used, which is fine for the purposes of latent entropy. But it was missing out on the cycle counter that was also being mixed in beside the latent entropy variable. So now, if the latent entropy gcc plugin isn't enabled, add_latent_entropy() will expand to a call to add_device_randomness(NULL, 0), which adds a cycle counter, without the absent latent entropy variable. - The RNG is now reseeded from a delayed worker, rather than on demand when used. Always running from a worker allows it to make use of the CPU RNG on platforms like S390x, whose instructions are too slow to do so from interrupts. It also has the effect of adding in new inputs more frequently with more regularity, amounting to a long term transcript of random values. Plus, it helps a bit with the upcoming vDSO implementation (which isn't yet ready for 6.2). - The jitter entropy algorithm now tries to execute on many different CPUs, round-robining, in hopes of hitting even more memory latencies and other unpredictable effects. It also will mix in a cycle counter when the entropy timer fires, in addition to being mixed in from the main loop, to account more explicitly for fluctuations in that timer firing. And the state it touches is now kept within the same cache line, so that it's assured that the different execution contexts will cause latencies. * tag 'random-6.2-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: (23 commits) random: include in the right header random: align entropy_timer_state to cache line random: mix in cycle counter when jitter timer fires random: spread out jitter callback to different CPUs random: remove extraneous period and add a missing one in comments efi: random: refresh non-volatile random seed when RNG is initialized vsprintf: initialize siphash key using notifier random: add back async readiness notifier random: reseed in delayed work rather than on-demand random: always mix cycle counter in add_latent_entropy() hw_random: use add_hwgenerator_randomness() for early entropy random: modernize documentation comment on get_random_bytes() random: adjust comment to account for removed function random: remove early archrandom abstraction random: use random.trust_{bootloader,cpu} command line option only stackprotector: actually use get_random_canary() stackprotector: move get_random_canary() into stackprotector.h treewide: use get_random_u32_inclusive() when possible treewide: use get_random_u32_{above,below}() instead of manual loop treewide: use get_random_u32_below() instead of deprecated function ...

tipc: call tipc_lxc_xmit without holding node_read_lock

2022-12-07T10:32:04Z

When sending packets between nodes in netns, it calls tipc_lxc_xmit() for peer node to receive the packets where tipc_sk_mcast_rcv()/tipc_sk_rcv() might be called, and it's pretty much like in tipc_rcv(). Currently the local 'node rw lock' is held during calling tipc_lxc_xmit() to protect the peer_net not being freed by another thread. However, when receiving these packets, tipc_node_add_conn() might be called where the peer 'node rw lock' is acquired. Then a dead lock warning is triggered by lockdep detector, although it is not a real dead lock: WARNING: possible recursive locking detected -------------------------------------------- conn_server/1086 is trying to acquire lock: ffff8880065cb020 (&n->lock#2){++--}-{2:2}, \ at: tipc_node_add_conn.cold.76+0xaa/0x211 [tipc] but task is already holding lock: ffff8880065cd020 (&n->lock#2){++--}-{2:2}, \ at: tipc_node_xmit+0x285/0xb30 [tipc] other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&n->lock#2); lock(&n->lock#2); *** DEADLOCK *** May be due to missing lock nesting notation 4 locks held by conn_server/1086: #0: ffff8880036d1e40 (sk_lock-AF_TIPC){+.+.}-{0:0}, \ at: tipc_accept+0x9c0/0x10b0 [tipc] #1: ffff8880036d5f80 (sk_lock-AF_TIPC/1){+.+.}-{0:0}, \ at: tipc_accept+0x363/0x10b0 [tipc] #2: ffff8880065cd020 (&n->lock#2){++--}-{2:2}, \ at: tipc_node_xmit+0x285/0xb30 [tipc] #3: ffff888012e13370 (slock-AF_TIPC){+...}-{2:2}, \ at: tipc_sk_rcv+0x2da/0x1b40 [tipc] Call Trace: dump_stack_lvl+0x44/0x5b __lock_acquire.cold.77+0x1f2/0x3d7 lock_acquire+0x1d2/0x610 _raw_write_lock_bh+0x38/0x80 tipc_node_add_conn.cold.76+0xaa/0x211 [tipc] tipc_sk_finish_conn+0x21e/0x640 [tipc] tipc_sk_filter_rcv+0x147b/0x3030 [tipc] tipc_sk_rcv+0xbb4/0x1b40 [tipc] tipc_lxc_xmit+0x225/0x26b [tipc] tipc_node_xmit.cold.82+0x4a/0x102 [tipc] __tipc_sendstream+0x879/0xff0 [tipc] tipc_accept+0x966/0x10b0 [tipc] do_accept+0x37d/0x590 This patch avoids this warning by not holding the 'node rw lock' before calling tipc_lxc_xmit(). As to protect the 'peer_net', rcu_read_lock() should be enough, as in cleanup_net() when freeing the netns, it calls synchronize_rcu() before the free is continued. Also since tipc_lxc_xmit() is like the RX path in tipc_rcv(), it makes sense to call it under rcu_read_lock(). Note that the right lock order must be: rcu_read_lock(); tipc_node_read_lock(n); tipc_node_read_unlock(n); tipc_lxc_xmit(); rcu_read_unlock(); instead of: tipc_node_read_lock(n); rcu_read_lock(); tipc_node_read_unlock(n); tipc_lxc_xmit(); rcu_read_unlock(); and we have to call tipc_node_read_lock/unlock() twice in tipc_node_xmit(). Fixes: f73b12812a3d ("tipc: improve throughput between nodes in netns") Reported-by: Shuang Li Signed-off-by: Xin Long Link: https://lore.kernel.org/r/5bdd1f8fee9db695cfff4528a48c9b9d0523fb00.1670110641.git.lucien.xin@gmail.com Signed-off-by: Paolo Abeni

tipc: Fix potential OOB in tipc_link_proto_rcv()

2022-12-06T11:58:38Z

Fix the potential risk of OOB if skb_linearize() fails in tipc_link_proto_rcv(). Fixes: 5cbb28a4bf65 ("tipc: linearize arriving NAME_DISTR and LINK_PROTO buffers") Signed-off-by: YueHaibing Link: https://lore.kernel.org/r/20221203094635.29024-1-yuehaibing@huawei.com Signed-off-by: Paolo Abeni

tipc: re-fetch skb cb after tipc_msg_validate

2022-11-29T02:07:31Z

As the call trace shows, the original skb was freed in tipc_msg_validate(), and dereferencing the old skb cb would cause an use-after-free crash. BUG: KASAN: use-after-free in tipc_crypto_rcv_complete+0x1835/0x2240 [tipc] Call Trace: tipc_crypto_rcv_complete+0x1835/0x2240 [tipc] tipc_crypto_rcv+0xd32/0x1ec0 [tipc] tipc_rcv+0x744/0x1150 [tipc] ... Allocated by task 47078: kmem_cache_alloc_node+0x158/0x4d0 __alloc_skb+0x1c1/0x270 tipc_buf_acquire+0x1e/0xe0 [tipc] tipc_msg_create+0x33/0x1c0 [tipc] tipc_link_build_proto_msg+0x38a/0x2100 [tipc] tipc_link_timeout+0x8b8/0xef0 [tipc] tipc_node_timeout+0x2a1/0x960 [tipc] call_timer_fn+0x2d/0x1c0 ... Freed by task 47078: tipc_msg_validate+0x7b/0x440 [tipc] tipc_crypto_rcv_complete+0x4b5/0x2240 [tipc] tipc_crypto_rcv+0xd32/0x1ec0 [tipc] tipc_rcv+0x744/0x1150 [tipc] This patch fixes it by re-fetching the skb cb from the new allocated skb after calling tipc_msg_validate(). Fixes: fc1b6d6de220 ("tipc: introduce TIPC encryption & authentication") Reported-by: Shuang Li Signed-off-by: Xin Long Link: https://lore.kernel.org/r/1b1cdba762915325bd8ef9a98d0276eb673df2a5.1669398403.git.lucien.xin@gmail.com Signed-off-by: Jakub Kicinski

use less confusing names for iov_iter direction initializers

2022-11-25T18:01:55Z

READ/WRITE proved to be actively confusing - the meanings are "data destination, as used with read(2)" and "data source, as used with write(2)", but people keep interpreting those as "we read data from it" and "we write data to it", i.e. exactly the wrong way. Call them ITER_DEST and ITER_SOURCE - at least that is harder to misinterpret... Signed-off-by: Al Viro

tipc: check skb_linearize() return value in tipc_disc_rcv()

2022-11-22T04:50:24Z

If skb_linearize() fails in tipc_disc_rcv(), we need to free the skb instead of handle it. Fixes: 25b0b9c4e835 ("tipc: handle collisions of 32-bit node address hash values") Signed-off-by: YueHaibing Acked-by: Jon Maloy Link: https://lore.kernel.org/r/20221119072832.7896-1-yuehaibing@huawei.com Signed-off-by: Jakub Kicinski