On Tue, Feb 28, 2023 at 4:45 AM Jan Kara <jack@xxxxxxx> wrote: > > On Tue 21-02-23 21:09:23, Palash Oswal wrote: > > Hello, > > I found the following issue using syzkaller on: > > HEAD commit : e60276b8c11ab4a8be23807bc67b04 > > 8cfb937dfa (v6.0.8) > > git tree: stable > > > > C Reproducer : https://gist.github.com/oswalpalash/bed0eba75def3cdd34a285428e9bcdc4 > > Kernel .config : > > https://gist.github.com/oswalpalash/0962c70d774e5ec736a047bba917cecb > > > > Console log : > > > > ================================================================== > > BUG: KASAN: use-after-free in __list_del_entry_valid+0xf2/0x110 > > Read of size 8 at addr ffff8880273c4358 by task syz-executor.1/6475 > > OK, so FAT inode was on writeback list (through inode->i_io_list) when > being freed. This should be fixed by commit 4e3c51f4e805 ("fs: do not > update freeing inode i_io_list"). Can you check please? > > Honza > I have verified that the commit fixes the bug. Tested against v6.0.11 on the stable tree. Thanks > > > > CPU: 0 PID: 6475 Comm: syz-executor.1 Not tainted 6.0.8-pasta #2 > > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > > 1.13.0-1ubuntu1.1 04/01/2014 > > Call Trace: > > <TASK> > > dump_stack_lvl+0xcd/0x134 > > print_report.cold+0xe5/0x63a > > kasan_report+0x8a/0x1b0 > > __list_del_entry_valid+0xf2/0x110 > > inode_cgwb_move_to_attached+0x2ee/0x4e0 > > writeback_single_inode+0x3fa/0x510 > > write_inode_now+0x16a/0x1e0 > > blkdev_flush_mapping+0x168/0x220 > > blkdev_put_whole+0xd1/0xf0 > > blkdev_put+0x29b/0x700 > > deactivate_locked_super+0x8c/0xf0 > > deactivate_super+0xad/0xd0 > > cleanup_mnt+0x347/0x4b0 > > task_work_run+0xe0/0x1a0 > > exit_to_user_mode_prepare+0x25d/0x270 > > syscall_exit_to_user_mode+0x19/0x50 > > do_syscall_64+0x42/0xb0 > > entry_SYSCALL_64_after_hwframe+0x63/0xcd > > RIP: 0033:0x7f22bd29143b > > Code: ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 90 f3 0f 1e fa 31 f6 > > e9 05 00 00 00 0f 1f 44 00 00 f3 0f 1e fa b8 a6 00 00 00 0f 05 <48> 3d > > 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 > > RSP: 002b:00007ffe505103b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 > > RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f22bd29143b > > RDX: 00007f22bd228a90 RSI: 000000000000000a RDI: 00007ffe50510480 > > RBP: 00007ffe50510480 R08: 00007f22bd2fba1f R09: 00007ffe50510240 > > R10: 00000000fffffffb R11: 0000000000000246 R12: 00007f22bd2fb9f8 > > R13: 00007ffe50511520 R14: 0000555556f4bd90 R15: 0000000000000032 > > </TASK> > > > > Allocated by task 7810: > > kasan_save_stack+0x1e/0x40 > > __kasan_slab_alloc+0x85/0xb0 > > kmem_cache_alloc_lru+0x25b/0xfb0 > > fat_alloc_inode+0x23/0x1e0 > > alloc_inode+0x61/0x1e0 > > new_inode_pseudo+0x13/0x80 > > new_inode+0x1b/0x40 > > fat_build_inode+0x146/0x2d0 > > vfat_create+0x249/0x390 > > lookup_open+0x10bc/0x1640 > > path_openat+0xa42/0x2840 > > do_filp_open+0x1ca/0x2a0 > > do_sys_openat2+0x61b/0x990 > > do_sys_open+0xc3/0x140 > > do_syscall_64+0x35/0xb0 > > entry_SYSCALL_64_after_hwframe+0x63/0xcd > > > > Freed by task 16: > > kasan_save_stack+0x1e/0x40 > > kasan_set_track+0x21/0x30 > > kasan_set_free_info+0x20/0x30 > > __kasan_slab_free+0xf5/0x180 > > kmem_cache_free.part.0+0xfc/0x4a0 > > i_callback+0x3f/0x70 > > rcu_core+0x785/0x1720 > > __do_softirq+0x1d0/0x908 > > > > Last potentially related work creation: > > kasan_save_stack+0x1e/0x40 > > __kasan_record_aux_stack+0x7e/0x90 > > call_rcu+0x99/0x740 > > destroy_inode+0x129/0x1b0 > > iput.part.0+0x5cd/0x800 > > iput+0x58/0x70 > > dentry_unlink_inode+0x2e2/0x4a0 > > __dentry_kill+0x374/0x5e0 > > dput+0x656/0xbe0 > > __fput+0x3cc/0xa90 > > task_work_run+0xe0/0x1a0 > > exit_to_user_mode_prepare+0x25d/0x270 > > syscall_exit_to_user_mode+0x19/0x50 > > do_syscall_64+0x42/0xb0 > > entry_SYSCALL_64_after_hwframe+0x63/0xcd > > > > The buggy address belongs to the object at ffff8880273c4080 > > which belongs to the cache fat_inode_cache of size 1488 > > The buggy address is located 728 bytes inside of > > 1488-byte region [ffff8880273c4080, ffff8880273c4650) > > > > The buggy address belongs to the physical page: > > page:ffffea00009cf100 refcount:1 mapcount:0 mapping:0000000000000000 > > index:0xffff8880273c4ffe pfn:0x273c4 > > flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) > > raw: 00fff00000000200 ffffea00009cf0c8 ffff88801820e450 ffff888103e00e00 > > raw: ffff8880273c4ffe ffff8880273c4080 0000000100000002 0000000000000000 > > page dumped because: kasan: bad access detected > > page_owner tracks the page as allocated > > page last allocated via order 0, migratetype Reclaimable, gfp_mask > > 0x242050(__GFP_IO|__GFP_NOWARN|__GFP_COMP|__GFP_THISNODE|__GFP_RECLAIMABLE), > > pid 7810, tgid 7808 (syz-executor.1), ts 50543388569, free_ts > > 21285403579 > > prep_new_page+0x2c6/0x350 > > get_page_from_freelist+0xae9/0x3a80 > > __alloc_pages+0x321/0x710 > > cache_grow_begin+0x75/0x360 > > kmem_cache_alloc_lru+0xe72/0xfb0 > > fat_alloc_inode+0x23/0x1e0 > > alloc_inode+0x61/0x1e0 > > new_inode_pseudo+0x13/0x80 > > new_inode+0x1b/0x40 > > fat_fill_super+0x1c37/0x3710 > > mount_bdev+0x34d/0x410 > > legacy_get_tree+0x105/0x220 > > vfs_get_tree+0x89/0x2f0 > > path_mount+0x121b/0x1cb0 > > do_mount+0xf3/0x110 > > __x64_sys_mount+0x18f/0x230 > > page last free stack trace: > > free_pcp_prepare+0x5ab/0xd00 > > free_unref_page+0x19/0x410 > > slab_destroy+0x14/0x50 > > slabs_destroy+0x6a/0x90 > > ___cache_free+0x1e3/0x3b0 > > qlist_free_all+0x51/0x1c0 > > kasan_quarantine_reduce+0x13d/0x180 > > __kasan_slab_alloc+0x97/0xb0 > > kmem_cache_alloc+0x204/0xcc0 > > getname_flags+0xd2/0x5b0 > > vfs_fstatat+0x73/0xb0 > > __do_sys_newlstat+0x8b/0x110 > > do_syscall_64+0x35/0xb0 > > entry_SYSCALL_64_after_hwframe+0x63/0xcd > > > > Memory state around the buggy address: > > ffff8880273c4200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ffff8880273c4280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > >ffff8880273c4300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ^ > > ffff8880273c4380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ffff8880273c4400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ================================================================== > -- > Jan Kara <jack@xxxxxxxx> > SUSE Labs, CR
