Hello, syzbot found the following issue on: HEAD commit: 3e9bff3bbe13 Merge tag 'vfs-6.11-rc6.fixes' of gitolite.ke.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=11e9fb8d980000 kernel config: https://syzkaller.appspot.com/x/.config?x=522060455c43d52e dashboard link: https://syzkaller.appspot.com/bug?extid=d13dc01606d396f1a66e compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/2143e6626450/disk-3e9bff3b.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/20b63281b398/vmlinux-3e9bff3b.xz kernel image: https://storage.googleapis.com/syzbot-assets/d0aef7b01715/bzImage-3e9bff3b.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+d13dc01606d396f1a66e@xxxxxxxxxxxxxxxxxxxxxxxxx ===================================================== BUG: KMSAN: uninit-value in zswap_is_folio_same_filled mm/zswap.c:1371 [inline] BUG: KMSAN: uninit-value in zswap_store+0x13e7/0x2dd0 mm/zswap.c:1438 zswap_is_folio_same_filled mm/zswap.c:1371 [inline] zswap_store+0x13e7/0x2dd0 mm/zswap.c:1438 swap_writepage+0x11f/0x470 mm/page_io.c:198 shmem_writepage+0x1a75/0x1f70 mm/shmem.c:1536 pageout mm/vmscan.c:680 [inline] shrink_folio_list+0x577f/0x7cb0 mm/vmscan.c:1360 evict_folios+0x9bce/0xbc80 mm/vmscan.c:4580 try_to_shrink_lruvec+0x13a3/0x1750 mm/vmscan.c:4775 shrink_one+0x646/0xd20 mm/vmscan.c:4813 shrink_many mm/vmscan.c:4876 [inline] lru_gen_shrink_node mm/vmscan.c:4954 [inline] shrink_node+0x451a/0x50f0 mm/vmscan.c:5934 kswapd_shrink_node mm/vmscan.c:6762 [inline] balance_pgdat mm/vmscan.c:6954 [inline] kswapd+0x257e/0x4290 mm/vmscan.c:7223 kthread+0x3dd/0x540 kernel/kthread.c:389 ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Uninit was stored to memory at: memcpy_from_iter lib/iov_iter.c:73 [inline] iterate_bvec include/linux/iov_iter.h:122 [inline] iterate_and_advance2 include/linux/iov_iter.h:249 [inline] iterate_and_advance include/linux/iov_iter.h:271 [inline] __copy_from_iter lib/iov_iter.c:249 [inline] copy_page_from_iter_atomic+0x12bb/0x2ae0 lib/iov_iter.c:481 copy_folio_from_iter_atomic include/linux/uio.h:186 [inline] generic_perform_write+0x896/0x12e0 mm/filemap.c:4032 shmem_file_write_iter+0x2bd/0x2f0 mm/shmem.c:3074 do_iter_readv_writev+0x8a1/0xa40 vfs_iter_write+0x459/0xd50 fs/read_write.c:895 lo_write_bvec drivers/block/loop.c:243 [inline] lo_write_simple drivers/block/loop.c:264 [inline] do_req_filebacked drivers/block/loop.c:511 [inline] loop_handle_cmd drivers/block/loop.c:1910 [inline] loop_process_work+0x15ec/0x3750 drivers/block/loop.c:1945 loop_workfn+0x48/0x60 drivers/block/loop.c:1969 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xae0/0x1c40 kernel/workqueue.c:3312 worker_thread+0xea7/0x14d0 kernel/workqueue.c:3389 kthread+0x3dd/0x540 kernel/kthread.c:389 ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Uninit was created at: __alloc_pages_noprof+0x9d6/0xe70 mm/page_alloc.c:4718 alloc_pages_bulk_noprof+0x19e/0x21e0 mm/page_alloc.c:4643 btrfs_alloc_page_array fs/btrfs/extent_io.c:704 [inline] alloc_eb_folio_array+0x19c/0x750 fs/btrfs/extent_io.c:728 alloc_extent_buffer+0x75a/0x3ba0 fs/btrfs/extent_io.c:3109 btrfs_find_create_tree_block+0x46/0x60 fs/btrfs/disk-io.c:614 btrfs_init_new_buffer fs/btrfs/extent-tree.c:5026 [inline] btrfs_alloc_tree_block+0x415/0x1990 fs/btrfs/extent-tree.c:5139 btrfs_alloc_log_tree_node fs/btrfs/disk-io.c:951 [inline] btrfs_add_log_tree+0x1b7/0x7a0 fs/btrfs/disk-io.c:999 start_log_trans fs/btrfs/tree-log.c:227 [inline] btrfs_log_inode_parent+0xa87/0x1c30 fs/btrfs/tree-log.c:7102 btrfs_log_dentry_safe+0x9a/0x100 fs/btrfs/tree-log.c:7207 btrfs_sync_file+0x15d9/0x2170 fs/btrfs/file.c:1773 vfs_fsync_range+0x20d/0x270 fs/sync.c:188 generic_write_sync include/linux/fs.h:2821 [inline] btrfs_do_write_iter+0xa17/0xb60 fs/btrfs/file.c:1515 btrfs_file_write_iter+0x38/0x50 fs/btrfs/file.c:1525 new_sync_write fs/read_write.c:497 [inline] vfs_write+0xb2f/0x1550 fs/read_write.c:590 ksys_write+0x20f/0x4c0 fs/read_write.c:643 __do_sys_write fs/read_write.c:655 [inline] __se_sys_write fs/read_write.c:652 [inline] __x64_sys_write+0x93/0xe0 fs/read_write.c:652 x64_sys_call+0x306a/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:2 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f CPU: 0 UID: 0 PID: 80 Comm: kswapd0 Tainted: G W 6.11.0-rc5-syzkaller-00015-g3e9bff3bbe13 #0 Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 ===================================================== --- 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@xxxxxxxxxxxxxxxx. 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 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
