On Mon, Jun 20, 2022 at 06:10:40AM +0000, bugzilla-daemon@xxxxxxxxxx wrote: > https://bugzilla.kernel.org/show_bug.cgi?id=216151 > > --- Comment #2 from Zorro Lang (zlang@xxxxxxxxxx) --- > Same panic on another machine (s390x): > > [10054.497558] run fstests generic/465 at 2022-06-19 16:09:21 > [10055.731299] > ================================================================= > = > [10055.731308] BUG: KASAN: use-after-free in _copy_to_iter+0x830/0x1030 > [10055.731324] Write of size 16 at addr 0000000090ebd000 by task nfsd/45999 > [10055.731328] > [10055.731331] CPU: 1 PID: 45999 Comm: nfsd Kdump: loaded Not tainted > 5.19.0-rc2 > + #1 > [10055.731335] Hardware name: IBM 8561 LT1 400 (z/VM 7.2.0) > [10055.731338] Call Trace: > [10055.731339] [<000000007bc24fda>] dump_stack_lvl+0xfa/0x150 > [10055.731345] [<000000007bc173bc>] > print_address_description.constprop.0+0x64/ > 0x3a8 > [10055.731351] [<000000007a98757e>] print_report+0xbe/0x230 > [10055.731356] [<000000007a987ba6>] kasan_report+0xa6/0x1e0 > [10055.731359] [<000000007a988fa4>] kasan_check_range+0x174/0x1c0 > [10055.731362] [<000000007a989a38>] memcpy+0x58/0x90 > [10055.731365] [<000000007affd0c0>] _copy_to_iter+0x830/0x1030 > [10055.731369] [<000000007affddd0>] copy_page_to_iter+0x510/0xcb0 > [10055.731372] [<000000007a7e986c>] filemap_read+0x52c/0x950 > [10055.731378] [<001bffff80599042>] xfs_file_buffered_read+0x1c2/0x410 [xfs] > [10055.731751] [<001bffff80599eba>] xfs_file_read_iter+0x28a/0x4c0 [xfs] > [10055.731975] [<000000007aa1084a>] do_iter_readv_writev+0x2ca/0x4c0 > [10055.731981] [<000000007aa1102a>] do_iter_read+0x23a/0x3a0 > [10055.731984] [<001bffff80f58d30>] nfsd_readv+0x1e0/0x710 [nfsd] > [10055.732070] [<001bffff80fa2f88>] nfsd4_encode_read_plus_data+0x3a8/0x770 > [nf > sd] > [10055.732129] [<001bffff80fa5010>] nfsd4_encode_read_plus+0x3e0/0xaa0 [nfsd] > [10055.732188] [<001bffff80fbc0ac>] nfsd4_encode_operation+0x21c/0xab0 [nfsd] > [10055.732249] [<001bffff80f9ca7e>] nfsd4_proc_compound+0x125e/0x21a0 [nfsd] > [10055.732307] [<001bffff80f441aa>] nfsd_dispatch+0x44a/0xc40 [nfsd] > [10055.732362] [<001bffff80b8d00c>] svc_process_common+0x92c/0x1cd0 [sunrpc] > [10055.732500] [<001bffff80b8e6ac>] svc_process+0x2fc/0x4c0 [sunrpc] > [10055.732579] [<001bffff80f42f4e>] nfsd+0x31e/0x600 [nfsd] > [10055.732634] [<000000007a2cc514>] kthread+0x2a4/0x360 > [10055.732640] [<000000007a186a5a>] __ret_from_fork+0x8a/0xf0 > [10055.732645] [<000000007bc5575a>] ret_from_fork+0xa/0x40 This doesn't look like an XFS problem. The _copy_to_iter() call that is tripping up here is copying from the page cache page to the buffer supplied to XFS by the NFSD in the iov_iter structure. We know that because it's a memory write operation that is triggering (read from page cache page, write to iov_iter buffer) here. > [10055.732650] 1 lock held by nfsd/45999: > [10055.732653] #0: 000000009cc7fb38 (&sb->s_type->i_mutex_key#13){++++}-{3:3}, > at: xfs_ilock+0x2fa/0x4e0 [xfs] > [10055.732887] > [10055.732888] Allocated by task 601543: > [10055.732890] kasan_save_stack+0x34/0x60 > [10055.732893] __kasan_slab_alloc+0x84/0xb0 > [10055.732896] kmem_cache_alloc+0x1e2/0x3d0 > [10055.732900] security_file_alloc+0x3a/0x150 > [10055.732906] __alloc_file+0xc0/0x210 > [10055.732908] alloc_empty_file+0x5c/0x140 > [10055.732911] path_openat+0xf8/0x700 > [10055.732914] do_filp_open+0x1b0/0x390 > [10055.732917] do_sys_openat2+0x134/0x3c0 > [10055.732920] do_sys_open+0xdc/0x120 > [10055.732922] do_syscall+0x22c/0x330 > [10055.732925] __do_syscall+0xce/0xf0 > [10055.732928] system_call+0x82/0xb0 > [10055.732931] > [10055.732932] Freed by task 601543: > [10055.732933] kasan_save_stack+0x34/0x60 > [10055.732935] kasan_set_track+0x36/0x50 > [10055.732937] kasan_set_free_info+0x34/0x60 > [10055.732940] __kasan_slab_free+0x106/0x150 > [10055.732942] slab_free_freelist_hook+0x148/0x230 > [10055.732946] kmem_cache_free+0x132/0x370 > [10055.732948] __fput+0x2b2/0x700 > [10055.732950] task_work_run+0xf4/0x1b0 > [10055.732952] exit_to_user_mode_prepare+0x286/0x290 > [10055.732957] __do_syscall+0xce/0xf0 > [10055.732959] system_call+0x82/0xb0 And that memory was last used as a struct file *, again something that XFS does not allocate but will be allocated by the NFSD as it opens and closes the files it receives requests to process for... > [10058.575635] Call Trace: > [10058.575638] [<000000007a989e3c>] qlist_free_all+0x9c/0x130 > [10058.575643] ([<000000007a989e1e>] qlist_free_all+0x7e/0x130) > [10058.575647] [<000000007a98a45a>] kasan_quarantine_reduce+0x16a/0x1c0 > [10058.575652] [<000000007a98720e>] __kasan_slab_alloc+0x9e/0xb0 > [10058.575657] [<000000007a9810a4>] __kmalloc+0x214/0x440 > [10058.575663] [<000000007ab19aa6>] inotify_handle_inode_event+0x1b6/0x7d0 > [10058.575669] [<000000007ab0ee74>] > fsnotify_handle_inode_event.isra.0+0x1c4/0x > 2f0 > [10058.575674] [<000000007ab0f490>] send_to_group+0x4f0/0x6c0 > [10058.575678] [<000000007ab0fe14>] fsnotify+0x654/0xb30 > [10058.575682] [<000000007ab10ca2>] __fsnotify_parent+0x372/0x780 > [10058.575687] [<000000007aa7eb9e>] notify_change+0x96e/0xcf0 > [10058.575693] [<000000007aa0a0c8>] do_truncate+0x108/0x190 > [10058.575699] [<000000007aa0aafc>] do_sys_ftruncate+0x31c/0x600 > [10058.575703] [<000000007a18da8c>] do_syscall+0x22c/0x330 > [10058.575709] [<000000007bc2cb6e>] __do_syscall+0xce/0xf0 > [10058.575716] [<000000007bc55722>] system_call+0x82/0xb0 > [10058.575722] INFO: lockdep is turned off. > [10058.575725] Last Breaking-Event-Address: > [10058.575727] [<000000007a985860>] ___cache_free+0x150/0x2a0 > [10058.575733] ---[ end trace 0000000000000000 ]--- And this subsequent oops has doesn't have anything to do with XFS either - this is indicative of slab cache (memory heap) corruption causing stuff to go badly wrong. Hence I think XFS is messenger here - something is corrupting the heap and an NFSD->XFS code path is the first to trip over it. Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx
