Wind River Support Network

Description

In the Linux kernel, the following vulnerability has been resolved:EOL][EOL]dm: don't attempt to queue IO under RCU protection[EOL][EOL]dm looks up the table for IO based on the request type, with an[EOL]assumption that if the request is marked REQ_NOWAIT, it's fine to[EOL]attempt to submit that IO while under RCU read lock protection. This[EOL]is not OK, as REQ_NOWAIT just means that we should not be sleeping[EOL]waiting on other IO, it does not mean that we can't potentially[EOL]schedule.[EOL][EOL]A simple test case demonstrates this quite nicely:[EOL][EOL]int main(int argc, char *argv[])[EOL]{[EOL]        struct iovec iov;[EOL]        int fd;[EOL][EOL]        fd = open("/dev/dm-0", O_RDONLY  ( O_DIRECT);[EOL)        posix_memalign(&iov.iov_base, 4096, 4096);[EOL]        iov.iov_len = 4096;[EOL]        preadv2(fd, &iov, 1, 0, RWF_NOWAIT);[EOL]        return 0;[EOL]}[EOL][EOL]which will instantly spew:[EOL][EOL]BUG: sleeping function called from invalid context at include/linux/sched/mm.h:306[EOL]in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 5580, name: dm-nowait[EOL]preempt_count: 0, expected: 0[EOL]RCU nest depth: 1, expected: 0[EOL]INFO: lockdep is turned off.[EOL]CPU: 7 PID: 5580 Comm: dm-nowait Not tainted 6.6.0-rc1-g39956d2dcd81 #132[EOL]Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014[EOL]Call Trace:[EOL] <TASK>[EOL] dump_stack_lvl+0x11d/0x1b0[EOL] __might_resched+0x3c3/0x5e0[EOL] ? preempt_count_sub+0x150/0x150[EOL] mempool_alloc+0x1e2/0x390[EOL] ? mempool_resize+0x7d0/0x7d0[EOL] ? lock_sync+0x190/0x190[EOL] ? lock_release+0x4b7/0x670[EOL] ? internal_get_user_pages_fast+0x868/0x2d40[EOL] bio_alloc_bioset+0x417/0x8c0[EOL] ? bvec_alloc+0x200/0x200[EOL] ? internal_get_user_pages_fast+0xb8c/0x2d40[EOL] bio_alloc_clone+0x53/0x100[EOL] dm_submit_bio+0x27f/0x1a20[EOL] ? lock_release+0x4b7/0x670[EOL] ? blk_try_enter_queue+0x1a0/0x4d0[EOL] ? dm_dax_direct_access+0x260/0x260[EOL] ? rcu_is_watching+0x12/0xb0[EOL] ? blk_try_enter_queue+0x1cc/0x4d0[EOL] __submit_bio+0x239/0x310[EOL] ? __bio_queue_enter+0x700/0x700[EOL] ? kvm_clock_get_cycles+0x40/0x60[EOL] ? ktime_get+0x285/0x470[EOL] submit_bio_noacct_nocheck+0x4d9/0xb80[EOL] ? should_fail_request+0x80/0x80[EOL] ? preempt_count_sub+0x150/0x150[EOL] ? lock_release+0x4b7/0x670[EOL] ? __bio_add_page+0x143/0x2d0[EOL] ? iov_iter_revert+0x27/0x360[EOL] submit_bio_noacct+0x53e/0x1b30[EOL] submit_bio_wait+0x10a/0x230[EOL] ? submit_bio_wait_endio+0x40/0x40[EOL] __blkdev_direct_IO_simple+0x4f8/0x780[EOL] ? blkdev_bio_end_io+0x4c0/0x4c0[EOL] ? stack_trace_save+0x90/0xc0[EOL] ? __bio_clone+0x3c0/0x3c0[EOL] ? lock_release+0x4b7/0x670[EOL] ? lock_sync+0x190/0x190[EOL] ? atime_needs_update+0x3bf/0x7e0[EOL] ? timestamp_truncate+0x21b/0x2d0[EOL] ? inode_owner_or_capable+0x240/0x240[EOL] blkdev_direct_IO.part.0+0x84a/0x1810[EOL] ? rcu_is_watching+0x12/0xb0[EOL] ? lock_release+0x4b7/0x670[EOL] ? blkdev_read_iter+0x40d/0x530[EOL] ? reacquire_held_locks+0x4e0/0x4e0[EOL] ? __blkdev_direct_IO_simple+0x780/0x780[EOL] ? rcu_is_watching+0x12/0xb0[EOL] ? __mark_inode_dirty+0x297/0xd50[EOL] ? preempt_count_add+0x72/0x140[EOL] blkdev_read_iter+0x2a4/0x530[EOL] do_iter_readv_writev+0x2f2/0x3c0[EOL] ? generic_copy_file_range+0x1d0/0x1d0[EOL] ? fsnotify_perm.part.0+0x25d/0x630[EOL] ? security_file_permission+0xd8/0x100[EOL] do_iter_read+0x31b/0x880[EOL] ? import_iovec+0x10b/0x140[EOL] vfs_readv+0x12d/0x1a0[EOL] ? vfs_iter_read+0xb0/0xb0[EOL] ? rcu_is_watching+0x12/0xb0[EOL] ? rcu_is_watching+0x12/0xb0[EOL] ? lock_release+0x4b7/0x670[EOL] do_preadv+0x1b3/0x260[EOL] ? do_readv+0x370/0x370[EOL] __x64_sys_preadv2+0xef/0x150[EOL] do_syscall_64+0x39/0xb0[EOL] entry_SYSCALL_64_after_hwframe+0x63/0xcd[EOL]RIP: 0033:0x7f5af41ad806[EOL]Code: 41 54 41 89 fc 55 44 89 c5 53 48 89 cb 48 83 ec 18 80 3d e4 dd 0d 00 00 74 7a 45 89 c1 49 89 ca 45 31 c0 b8 47 01 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 be 00 00 00 48 85 c0 79 4a 48 8b 0d da 55[EOL]RSP: 002b:00007ffd3145c7f0 EFLAGS: 00000246 ORIG_RAX: 0000000000000147[EOL]RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5af41ad806[EOL]RDX: 0000000000000001 RSI: 00007ffd3145c850 RDI: 0000000000000003[EOL]RBP: 0000000000000008 R08: 0000000000000000 R09: 0000000000000008[EOL]R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003[EOL]R13: 00007ffd3145c850 R14: 000055f5f0431dd8 R15: 0000000000000001[EOL] </TASK>[EOL][EOL]where in fact it is[EOL]---truncated---

CVEs

• CVE-2023-53860