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Date: Tue, 19 Mar 2024 06:56:41 -0700
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Subject: Re: [syzbot] Re: [syzbot] [v9fs?] KMSAN: uninit-value in v9fs_evict_inode
From: syzbot <syzbot+eb83fe1cce5833cd66a0@syzkaller.appspotmail.com>
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Subject: Re: [syzbot] [v9fs?] KMSAN: uninit-value in v9fs_evict_inode
Author: eric.vanhensbergen@linux.dev

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs.git b4/fix-evict-uninitialized-value

March 16, 2024 at 6:15 AM, "syzbot" <syzbot+eb83fe1cce5833cd66a0@syzkaller.appspotmail.com> wrote:
> 
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit: 66a27abac311 Merge tag 'powerpc-6.9-1' of git://git.kernel..
> 
> git tree: upstream
> 
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=147b32a5180000
> 
> kernel config: https://syzkaller.appspot.com/x/.config?x=48bb382b96e7eda7
> 
> dashboard link: https://syzkaller.appspot.com/bug?extid=eb83fe1cce5833cd66a0
> 
> compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
> 
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12598006180000
> 
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=105d8aa5180000
> 
> Downloadable assets:
> 
> disk image: https://storage.googleapis.com/syzbot-assets/37968fa0451e/disk-66a27aba.raw.xz
> 
> vmlinux: https://storage.googleapis.com/syzbot-assets/5b288c5c3088/vmlinux-66a27aba.xz
> 
> kernel image: https://storage.googleapis.com/syzbot-assets/792ddbf8146d/bzImage-66a27aba.xz
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> 
> Reported-by: syzbot+eb83fe1cce5833cd66a0@syzkaller.appspotmail.com
> 
> =====================================================
> 
> BUG: KMSAN: uninit-value in fscache_relinquish_cookie include/linux/fscache.h:307 [inline]
> 
> BUG: KMSAN: uninit-value in v9fs_evict_inode+0x109/0x130 fs/9p/vfs_inode.c:356
> 
>  fscache_relinquish_cookie include/linux/fscache.h:307 [inline]
> 
>  v9fs_evict_inode+0x109/0x130 fs/9p/vfs_inode.c:356
> 
>  evict+0x3ae/0xa60 fs/inode.c:667
> 
>  iput_final fs/inode.c:1741 [inline]
> 
>  iput+0x9ca/0xe10 fs/inode.c:1767
> 
>  iget_failed+0x15e/0x180 fs/bad_inode.c:248
> 
>  v9fs_fid_iget_dotl+0x375/0x570 fs/9p/vfs_inode_dotl.c:96
> 
>  v9fs_get_inode_from_fid fs/9p/v9fs.h:230 [inline]
> 
>  v9fs_mount+0xc02/0x12b0 fs/9p/vfs_super.c:142
> 
>  legacy_get_tree+0x114/0x290 fs/fs_context.c:662
> 
>  vfs_get_tree+0xa7/0x570 fs/super.c:1779
> 
>  do_new_mount+0x71f/0x15e0 fs/namespace.c:3352
> 
>  path_mount+0x742/0x1f20 fs/namespace.c:3679
> 
>  do_mount fs/namespace.c:3692 [inline]
> 
>  __do_sys_mount fs/namespace.c:3898 [inline]
> 
>  __se_sys_mount+0x725/0x810 fs/namespace.c:3875
> 
>  __x64_sys_mount+0xe4/0x150 fs/namespace.c:3875
> 
>  do_syscall_64+0xd5/0x1f0
> 
>  entry_SYSCALL_64_after_hwframe+0x6d/0x75
> 
> Uninit was created at:
> 
>  __alloc_pages+0x9d6/0xe70 mm/page_alloc.c:4598
> 
>  __alloc_pages_node include/linux/gfp.h:238 [inline]
> 
>  alloc_pages_node include/linux/gfp.h:261 [inline]
> 
>  alloc_slab_page mm/slub.c:2175 [inline]
> 
>  allocate_slab mm/slub.c:2338 [inline]
> 
>  new_slab+0x2de/0x1400 mm/slub.c:2391
> 
>  ___slab_alloc+0x1184/0x33d0 mm/slub.c:3525
> 
>  __slab_alloc mm/slub.c:3610 [inline]
> 
>  __slab_alloc_node mm/slub.c:3663 [inline]
> 
>  slab_alloc_node mm/slub.c:3835 [inline]
> 
>  kmem_cache_alloc_lru+0x6d7/0xbe0 mm/slub.c:3864
> 
>  alloc_inode_sb include/linux/fs.h:3089 [inline]
> 
>  v9fs_alloc_inode+0x62/0x130 fs/9p/vfs_inode.c:228
> 
>  alloc_inode+0x86/0x460 fs/inode.c:261
> 
>  iget_locked+0x2bf/0xee0 fs/inode.c:1280
> 
>  v9fs_fid_iget_dotl+0x7f/0x570 fs/9p/vfs_inode_dotl.c:62
> 
>  v9fs_get_inode_from_fid fs/9p/v9fs.h:230 [inline]
> 
>  v9fs_mount+0xc02/0x12b0 fs/9p/vfs_super.c:142
> 
>  legacy_get_tree+0x114/0x290 fs/fs_context.c:662
> 
>  vfs_get_tree+0xa7/0x570 fs/super.c:1779
> 
>  do_new_mount+0x71f/0x15e0 fs/namespace.c:3352
> 
>  path_mount+0x742/0x1f20 fs/namespace.c:3679
> 
>  do_mount fs/namespace.c:3692 [inline]
> 
>  __do_sys_mount fs/namespace.c:3898 [inline]
> 
>  __se_sys_mount+0x725/0x810 fs/namespace.c:3875
> 
>  __x64_sys_mount+0xe4/0x150 fs/namespace.c:3875
> 
>  do_syscall_64+0xd5/0x1f0
> 
>  entry_SYSCALL_64_after_hwframe+0x6d/0x75
> 
> CPU: 1 PID: 5014 Comm: syz-executor406 Not tainted 6.8.0-syzkaller-11136-g66a27abac311 #0
> 
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
> 
> =====================================================
> 
> ---
> 
> 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@googlegroups.com.
> 
> syzbot will keep track of this issue. See:
> 
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> 
> If the report is already addressed, let syzbot know by replying with:
> 
> #syz fix: exact-commit-title
> 
> If you want syzbot to run the reproducer, reply with:
> 
> #syz test: git://repo/address.git branch-or-commit-hash
> 
> If you attach or paste a git patch, syzbot will apply it before testing.
> 
> If you want to overwrite report's subsystems, reply with:
> 
> #syz set subsystems: new-subsystem
> 
> (See the list of subsystem names on the web dashboard)
> 
> If the report is a duplicate of another one, reply with:
> 
> #syz dup: exact-subject-of-another-report
> 
> If you want to undo deduplication, reply with:
> 
> #syz undup
>