user/sven/linux.git/fs/io_uring.c, branch v5.4.60

io_uring: Fix NULL pointer dereference in loop_rw_iter()

2020-08-19T06:16:29Z

commit 2dd2111d0d383df104b144e0d1f6b5a00cb7cd88 upstream. loop_rw_iter() does not check whether the file has a read or write function. This can lead to NULL pointer dereference when the user passes in a file descriptor that does not have read or write function. The crash log looks like this: [ 99.834071] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 99.835364] #PF: supervisor instruction fetch in kernel mode [ 99.836522] #PF: error_code(0x0010) - not-present page [ 99.837771] PGD 8000000079d62067 P4D 8000000079d62067 PUD 79d8c067 PMD 0 [ 99.839649] Oops: 0010 [#2] SMP PTI [ 99.840591] CPU: 1 PID: 333 Comm: io_wqe_worker-0 Tainted: G D 5.8.0 #2 [ 99.842622] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1 04/01/2014 [ 99.845140] RIP: 0010:0x0 [ 99.845840] Code: Bad RIP value. [ 99.846672] RSP: 0018:ffffa1c7c01ebc08 EFLAGS: 00010202 [ 99.848018] RAX: 0000000000000000 RBX: ffff92363bd67300 RCX: ffff92363d461208 [ 99.849854] RDX: 0000000000000010 RSI: 00007ffdbf696bb0 RDI: ffff92363bd67300 [ 99.851743] RBP: ffffa1c7c01ebc40 R08: 0000000000000000 R09: 0000000000000000 [ 99.853394] R10: ffffffff9ec692a0 R11: 0000000000000000 R12: 0000000000000010 [ 99.855148] R13: 0000000000000000 R14: ffff92363d461208 R15: ffffa1c7c01ebc68 [ 99.856914] FS: 0000000000000000(0000) GS:ffff92363dd00000(0000) knlGS:0000000000000000 [ 99.858651] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 99.860032] CR2: ffffffffffffffd6 CR3: 000000007ac66000 CR4: 00000000000006e0 [ 99.861979] Call Trace: [ 99.862617] loop_rw_iter.part.0+0xad/0x110 [ 99.863838] io_write+0x2ae/0x380 [ 99.864644] ? kvm_sched_clock_read+0x11/0x20 [ 99.865595] ? sched_clock+0x9/0x10 [ 99.866453] ? sched_clock_cpu+0x11/0xb0 [ 99.867326] ? newidle_balance+0x1d4/0x3c0 [ 99.868283] io_issue_sqe+0xd8f/0x1340 [ 99.869216] ? __switch_to+0x7f/0x450 [ 99.870280] ? __switch_to_asm+0x42/0x70 [ 99.871254] ? __switch_to_asm+0x36/0x70 [ 99.872133] ? lock_timer_base+0x72/0xa0 [ 99.873155] ? switch_mm_irqs_off+0x1bf/0x420 [ 99.874152] io_wq_submit_work+0x64/0x180 [ 99.875192] ? kthread_use_mm+0x71/0x100 [ 99.876132] io_worker_handle_work+0x267/0x440 [ 99.877233] io_wqe_worker+0x297/0x350 [ 99.878145] kthread+0x112/0x150 [ 99.878849] ? __io_worker_unuse+0x100/0x100 [ 99.879935] ? kthread_park+0x90/0x90 [ 99.880874] ret_from_fork+0x22/0x30 [ 99.881679] Modules linked in: [ 99.882493] CR2: 0000000000000000 [ 99.883324] ---[ end trace 4453745f4673190b ]--- [ 99.884289] RIP: 0010:0x0 [ 99.884837] Code: Bad RIP value. [ 99.885492] RSP: 0018:ffffa1c7c01ebc08 EFLAGS: 00010202 [ 99.886851] RAX: 0000000000000000 RBX: ffff92363acd7f00 RCX: ffff92363d461608 [ 99.888561] RDX: 0000000000000010 RSI: 00007ffe040d9e10 RDI: ffff92363acd7f00 [ 99.890203] RBP: ffffa1c7c01ebc40 R08: 0000000000000000 R09: 0000000000000000 [ 99.891907] R10: ffffffff9ec692a0 R11: 0000000000000000 R12: 0000000000000010 [ 99.894106] R13: 0000000000000000 R14: ffff92363d461608 R15: ffffa1c7c01ebc68 [ 99.896079] FS: 0000000000000000(0000) GS:ffff92363dd00000(0000) knlGS:0000000000000000 [ 99.898017] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 99.899197] CR2: ffffffffffffffd6 CR3: 000000007ac66000 CR4: 00000000000006e0 Fixes: 32960613b7c3 ("io_uring: correctly handle non ->{read,write}_iter() file_operations") Cc: stable@vger.kernel.org Signed-off-by: Guoyu Huang Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

io_uring: set ctx sq/cq entry count earlier

2020-08-19T06:16:24Z

commit bd74048108c179cea0ff52979506164c80f29da7 upstream. If we hit an earlier error path in io_uring_create(), then we will have accounted memory, but not set ctx->{sq,cq}_entries yet. Then when the ring is torn down in error, we use those values to unaccount the memory. Ensure we set the ctx entries before we're able to hit a potential error path. Cc: stable@vger.kernel.org Reported-by: Tomáš Chaloupka Tested-by: Tomáš Chaloupka Reviewed-by: Stefano Garzarella Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

io_uring: fix sq array offset calculation

2020-08-19T06:15:57Z

[ Upstream commit b36200f543ff07a1cb346aa582349141df2c8068 ] rings_size() sets sq_offset to the total size of the rings (the returned value which is used for memory allocation). This is wrong: sq array should be located within the rings, not after them. Set sq_offset to where it should be. Fixes: 75b28affdd6a ("io_uring: allocate the two rings together") Signed-off-by: Dmitry Vyukov Acked-by: Hristo Venev Cc: io-uring@vger.kernel.org Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

fs/io_uring.c: Fix uninitialized variable is referenced in io_submit_sqe

2020-08-19T06:15:53Z

the commit ("opcode>") caused another vulnerability. After io_get_req(), the sqe_submit struct in req is not initialized, but the following code defaults that req->submit.opcode is available. Signed-off-by: Liu Yong Signed-off-by: Sasha Levin

io_uring: Fix use-after-free in io_sq_wq_submit_work()

2020-08-11T13:33:33Z

when ctx->sqo_mm is zero, io_sq_wq_submit_work() frees 'req' without deleting it from 'task_list'. After that, 'req' is accessed in io_ring_ctx_wait_and_kill() which lead to a use-after-free. Signed-off-by: Guoyu Huang Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

io_uring: prevent re-read of sqe->opcode

2020-08-11T13:33:32Z

Liu reports that he can trigger a NULL pointer dereference with IORING_OP_SENDMSG, by changing the sqe->opcode after we've validated that the previous opcode didn't need a file and didn't assign one. Ensure we validate and read the opcode only once. Reported-by: Liu Yong Tested-by: Liu Yong Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

io_uring: make sure async workqueue is canceled on exit

2020-07-09T07:37:49Z

Track async work items that we queue, so we can safely cancel them if the ring is closed or the process exits. Newer kernels handle this automatically with io-wq, but the old workqueue based setup needs a bit of special help to get there. There's no upstream variant of this, as that would require backporting all the io-wq changes from 5.5 and on. Hence I made a one-off that ensures that we don't leak memory if we have async work items that need active cancelation (like socket IO). Reported-by: Agarwal, Anchal Tested-by: Agarwal, Anchal Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

io_uring: use kvfree() in io_sqe_buffer_register()

2020-06-17T14:40:26Z

commit a8c73c1a614f6da6c0b04c393f87447e28cb6de4 upstream. Use kvfree() to free the pages and vmas, since they are allocated by kvmalloc_array() in a loop. Fixes: d4ef647510b1 ("io_uring: avoid page allocation warnings") Signed-off-by: Denis Efremov Signed-off-by: Jens Axboe Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200605093203.40087-1-efremov@linux.com Signed-off-by: Greg Kroah-Hartman

io_uring: initialize ctx->sqo_wait earlier

2020-06-07T11:18:50Z

[ Upstream commit 583863ed918136412ddf14de2e12534f17cfdc6f ] Ensure that ctx->sqo_wait is initialized as soon as the ctx is allocated, instead of deferring it to the offload setup. This fixes a syzbot reported lockdep complaint, which is really due to trying to wake_up on an uninitialized wait queue: RSP: 002b:00007fffb1fb9aa8 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441319 RDX: 0000000000000001 RSI: 0000000020000140 RDI: 000000000000047b RBP: 0000000000010475 R08: 0000000000000001 R09: 00000000004002c8 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402260 R13: 00000000004022f0 R14: 0000000000000000 R15: 0000000000000000 INFO: trying to register non-static key. the code is fine but needs lockdep annotation. turning off the locking correctness validator. CPU: 1 PID: 7090 Comm: syz-executor222 Not tainted 5.7.0-rc1-next-20200415-syzkaller #0 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+0x188/0x20d lib/dump_stack.c:118 assign_lock_key kernel/locking/lockdep.c:913 [inline] register_lock_class+0x1664/0x1760 kernel/locking/lockdep.c:1225 __lock_acquire+0x104/0x4c50 kernel/locking/lockdep.c:4234 lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4934 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xbf kernel/locking/spinlock.c:159 __wake_up_common_lock+0xb4/0x130 kernel/sched/wait.c:122 io_cqring_ev_posted+0xa5/0x1e0 fs/io_uring.c:1160 io_poll_remove_all fs/io_uring.c:4357 [inline] io_ring_ctx_wait_and_kill+0x2bc/0x5a0 fs/io_uring.c:7305 io_uring_create fs/io_uring.c:7843 [inline] io_uring_setup+0x115e/0x22b0 fs/io_uring.c:7870 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x441319 Code: e8 5c ae 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 bb 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fffb1fb9aa8 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9 Reported-by: syzbot+8c91f5d054e998721c57@syzkaller.appspotmail.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

io_uring: honor original task RLIMIT_FSIZE

2020-04-17T08:50:16Z

commit 4ed734b0d0913e566a9d871e15d24eb240f269f7 upstream. With the previous fixes for number of files open checking, I added some debug code to see if we had other spots where we're checking rlimit() against the async io-wq workers. The only one I found was file size checking, which we should also honor. During write and fallocate prep, store the max file size and override that for the current ask if we're in io-wq worker context. Cc: stable@vger.kernel.org # 5.1+ Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman