On Thu, Sep 22, 2022 at 1:11 AM Ryusuke Konishi wrote: > > On Thu, Sep 22, 2022 at 1:02 AM syzbot wrote: > > > > Hello, > > > > syzbot found the following issue on: > > > > HEAD commit: a335366bad13 Merge tag 'gpio-fixes-for-v6.0-rc6' of git://.. > > git tree: upstream > > console+strace: https://syzkaller.appspot.com/x/log.txt?x=13af94f8880000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=98a30118ec9215e9 > > dashboard link: https://syzkaller.appspot.com/bug?extid=3974efaf68c77533b42d > > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11e17937080000 > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1570a75d080000 > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > Reported-by: syzbot+3974efaf68c77533b42d@xxxxxxxxxxxxxxxxxxxxxxxxx > > > > ================================================================== > > BUG: KASAN: use-after-free in nilfs_mdt_destroy+0x6f/0x80 fs/nilfs2/mdt.c:497 > > Read of size 8 at addr ffff888020124498 by task syz-executor134/3740 > > > > CPU: 0 PID: 3740 Comm: syz-executor134 Not tainted 6.0.0-rc5-syzkaller-00094-ga335366bad13 #0 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 > > Call Trace: > > <TASK> > > __dump_stack lib/dump_stack.c:88 [inline] > > dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 > > print_address_description mm/kasan/report.c:317 [inline] > > print_report.cold+0x2ba/0x719 mm/kasan/report.c:433 > > kasan_report+0xb1/0x1e0 mm/kasan/report.c:495 > > nilfs_mdt_destroy+0x6f/0x80 fs/nilfs2/mdt.c:497 > > nilfs_free_inode+0x3e/0x60 fs/nilfs2/super.c:168 > > i_callback fs/inode.c:249 [inline] > > alloc_inode+0x13b/0x230 fs/inode.c:274 > > new_inode_pseudo fs/inode.c:1019 [inline] > > new_inode+0x27/0x270 fs/inode.c:1047 > > nilfs_new_inode+0xca/0x830 fs/nilfs2/inode.c:334 > > nilfs_create fs/nilfs2/namei.c:85 [inline] > > nilfs_create+0xfe/0x300 fs/nilfs2/namei.c:75 > > vfs_create fs/namei.c:3115 [inline] > > vfs_create+0x3e9/0x670 fs/namei.c:3101 > > do_mknodat+0x3d9/0x530 fs/namei.c:3942 > > __do_sys_mknodat fs/namei.c:3970 [inline] > > __se_sys_mknodat fs/namei.c:3967 [inline] > > __x64_sys_mknodat+0xaa/0xe0 fs/namei.c:3967 > > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > > do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 > > entry_SYSCALL_64_after_hwframe+0x63/0xcd > > RIP: 0033:0x7f2443bec549 > > Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 > > RSP: 002b:00007ffdd9390cc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000103 > > RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f2443bec549 > > RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000005 > > RBP: 00007ffdd9390cf0 R08: 0000000000000001 R09: 00007ffdd9390d00 > > R10: 0000000000000103 R11: 0000000000000246 R12: 0000000000000003 > > R13: 00007ffdd9390d30 R14: 00007ffdd9390d10 R15: 0000000000000009 > > </TASK> > > > > Allocated by task 3621: > > kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 > > kasan_set_track mm/kasan/common.c:45 [inline] > > set_alloc_info mm/kasan/common.c:437 [inline] > > ____kasan_kmalloc mm/kasan/common.c:516 [inline] > > ____kasan_kmalloc mm/kasan/common.c:475 [inline] > > __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:525 > > kmalloc include/linux/slab.h:605 [inline] > > kzalloc include/linux/slab.h:733 [inline] > > nilfs_mdt_init+0x2c/0x1e0 fs/nilfs2/mdt.c:451 > > nilfs_sufile_read+0x191/0x5a0 fs/nilfs2/sufile.c:1183 > > nilfs_load_super_root fs/nilfs2/the_nilfs.c:130 [inline] > > load_nilfs+0x671/0x1330 fs/nilfs2/the_nilfs.c:269 > > nilfs_fill_super fs/nilfs2/super.c:1059 [inline] > > nilfs_mount+0xa9a/0xfb0 fs/nilfs2/super.c:1317 > > legacy_get_tree+0x105/0x220 fs/fs_context.c:610 > > vfs_get_tree+0x89/0x2f0 fs/super.c:1530 > > do_new_mount fs/namespace.c:3040 [inline] > > path_mount+0x1326/0x1e20 fs/namespace.c:3370 > > do_mount fs/namespace.c:3383 [inline] > > __do_sys_mount fs/namespace.c:3591 [inline] > > __se_sys_mount fs/namespace.c:3568 [inline] > > __x64_sys_mount+0x27f/0x300 fs/namespace.c:3568 > > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > > do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 > > entry_SYSCALL_64_after_hwframe+0x63/0xcd > > > > The buggy address belongs to the object at ffff888020124400 > > which belongs to the cache kmalloc-256 of size 256 > > The buggy address is located 152 bytes inside of > > 256-byte region [ffff888020124400, ffff888020124500) > > > > The buggy address belongs to the physical page: > > page:ffffea0000804900 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888020124a00 pfn:0x20124 > > head:ffffea0000804900 order:1 compound_mapcount:0 compound_pincount:0 > > flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) > > raw: 00fff00000010200 ffffea0001ff2508 ffff888011840708 ffff888011841b40 > > raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 > > page dumped because: kasan: bad access detected > > page_owner tracks the page as allocated > > page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 7456347523, free_ts 0 > > prep_new_page mm/page_alloc.c:2532 [inline] > > get_page_from_freelist+0x109b/0x2ce0 mm/page_alloc.c:4283 > > __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5515 > > alloc_page_interleave+0x1e/0x200 mm/mempolicy.c:2103 > > alloc_pages+0x22f/0x270 mm/mempolicy.c:2265 > > alloc_slab_page mm/slub.c:1824 [inline] > > allocate_slab+0x27e/0x3d0 mm/slub.c:1969 > > new_slab mm/slub.c:2029 [inline] > > ___slab_alloc+0x7f1/0xe10 mm/slub.c:3031 > > __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3118 > > slab_alloc_node mm/slub.c:3209 [inline] > > slab_alloc mm/slub.c:3251 [inline] > > __kmalloc+0x32b/0x340 mm/slub.c:4420 > > kmalloc include/linux/slab.h:605 [inline] > > kzalloc include/linux/slab.h:733 [inline] > > rh_call_control drivers/usb/core/hcd.c:514 [inline] > > rh_urb_enqueue drivers/usb/core/hcd.c:848 [inline] > > usb_hcd_submit_urb+0x661/0x2220 drivers/usb/core/hcd.c:1552 > > usb_submit_urb+0x86d/0x1880 drivers/usb/core/urb.c:594 > > usb_start_wait_urb+0x101/0x4b0 drivers/usb/core/message.c:58 > > usb_internal_control_msg drivers/usb/core/message.c:102 [inline] > > usb_control_msg+0x31c/0x4a0 drivers/usb/core/message.c:153 > > usb_get_string+0xbe/0x1b0 drivers/usb/core/message.c:843 > > usb_string_sub+0xfa/0x3d0 drivers/usb/core/message.c:882 > > usb_string+0x2fb/0x530 drivers/usb/core/message.c:987 > > usb_cache_string+0x82/0x140 drivers/usb/core/message.c:1029 > > page_owner free stack trace missing > > > > Memory state around the buggy address: > > ffff888020124380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > > ffff888020124400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > > >ffff888020124480: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc > > ^ > > ffff888020124500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > > ffff888020124580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > > ================================================================== > > > > > > --- > > This report is generated by a bot. It may contain errors. > > See https://goo.gl/tpsmEJ for more information about syzbot. > > syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. > > > > syzbot will keep track of this issue. See: > > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > > syzbot can test patches for this issue, for details see: > > https://goo.gl/tpsmEJ#testing-patches > > This looks like the same issue as the report [1]: > > [1] https://lore.kernel.org/all/CAFcO6XOcf1Jj2SeGt=jJV59wmhESeSKpfR0omdFRq+J9nD1vfQ@xxxxxxxxxxxxxx/T/#u > > The bug fix patch for this, is queued in the vfs tree with the title > "fs: fix UAF/GPF bug in nilfs_mdt_destroy" [2]: > > [2] https://lkml.kernel.org/r/20220816040859.659129-1-dzm91@xxxxxxxxxxx > > It's in the latest linux-next as well. > As the outlook for now, this patch would be merged to the mainline > after Linux kernel 6.0 is released, and then backported to stable > trees. > > Thanks, > Ryusuke Konishi #syz fix: fs: fix UAF/GPF bug in nilfs_mdt_destroy According to the stack trace, the crash at nilfs_mdt_destroy() has happened in the case where inode_init_alway() failed in alloc_inode(). This problem is exactly what the above patch fixes. Ryusuke Konishi
