From: Ye Bin yebin10@huawei.com
commit 5c099c4fdc438014d5893629e70a8ba934433ee8 upstream.
Syzbot report follow issue: ------------[ cut here ]------------ kernel BUG at fs/ext4/inline.c:227! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 3629 Comm: syz-executor212 Not tainted 6.1.0-rc5-syzkaller-00018-g59d0d52c30d4 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 RIP: 0010:ext4_write_inline_data+0x344/0x3e0 fs/ext4/inline.c:227 RSP: 0018:ffffc90003b3f368 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffff8880704e16c0 RCX: 0000000000000000 RDX: ffff888021763a80 RSI: ffffffff821e31a4 RDI: 0000000000000006 RBP: 000000000006818e R08: 0000000000000006 R09: 0000000000068199 R10: 0000000000000079 R11: 0000000000000000 R12: 000000000000000b R13: 0000000000068199 R14: ffffc90003b3f408 R15: ffff8880704e1c82 FS: 000055555723e3c0(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fffe8ac9080 CR3: 0000000079f81000 CR4: 0000000000350ee0 Call Trace: <TASK> ext4_write_inline_data_end+0x2a3/0x12f0 fs/ext4/inline.c:768 ext4_write_end+0x242/0xdd0 fs/ext4/inode.c:1313 ext4_da_write_end+0x3ed/0xa30 fs/ext4/inode.c:3063 generic_perform_write+0x316/0x570 mm/filemap.c:3764 ext4_buffered_write_iter+0x15b/0x460 fs/ext4/file.c:285 ext4_file_write_iter+0x8bc/0x16e0 fs/ext4/file.c:700 call_write_iter include/linux/fs.h:2191 [inline] do_iter_readv_writev+0x20b/0x3b0 fs/read_write.c:735 do_iter_write+0x182/0x700 fs/read_write.c:861 vfs_iter_write+0x74/0xa0 fs/read_write.c:902 iter_file_splice_write+0x745/0xc90 fs/splice.c:686 do_splice_from fs/splice.c:764 [inline] direct_splice_actor+0x114/0x180 fs/splice.c:931 splice_direct_to_actor+0x335/0x8a0 fs/splice.c:886 do_splice_direct+0x1ab/0x280 fs/splice.c:974 do_sendfile+0xb19/0x1270 fs/read_write.c:1255 __do_sys_sendfile64 fs/read_write.c:1323 [inline] __se_sys_sendfile64 fs/read_write.c:1309 [inline] __x64_sys_sendfile64+0x1d0/0x210 fs/read_write.c:1309 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd ---[ end trace 0000000000000000 ]---
Above issue may happens as follows: ext4_da_write_begin ext4_da_write_inline_data_begin ext4_da_convert_inline_data_to_extent ext4_clear_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA); ext4_da_write_end
ext4_run_li_request ext4_mb_prefetch ext4_read_block_bitmap_nowait ext4_validate_block_bitmap ext4_mark_group_bitmap_corrupted(sb, block_group, EXT4_GROUP_INFO_BBITMAP_CORRUPT) percpu_counter_sub(&sbi->s_freeclusters_counter,grp->bb_free); -> sbi->s_freeclusters_counter become zero ext4_da_write_begin if (ext4_nonda_switch(inode->i_sb)) -> As freeclusters_counter is zero will return true *fsdata = (void *)FALL_BACK_TO_NONDELALLOC; ext4_write_begin ext4_da_write_end if (write_mode == FALL_BACK_TO_NONDELALLOC) ext4_write_end if (inline_data) ext4_write_inline_data_end ext4_write_inline_data BUG_ON(pos + len > EXT4_I(inode)->i_inline_size); -> As inode is already convert to extent, so 'pos + len' > inline_size -> then trigger BUG.
To solve this issue, instead of checking ext4_has_inline_data() which is only cleared after data has been written back, check the EXT4_STATE_MAY_INLINE_DATA flag in ext4_write_end().
Fixes: f19d5870cbf7 ("ext4: add normal write support for inline data") Reported-by: syzbot+4faa160fa96bfba639f8@syzkaller.appspotmail.com Reported-by: Jun Nie jun.nie@linaro.org Signed-off-by: Ye Bin yebin10@huawei.com Link: https://lore.kernel.org/r/20221206144134.1919987-1-yebin@huaweicloud.com Signed-off-by: Theodore Ts'o tytso@mit.edu Cc: stable@kernel.org [ta: Fix conflict in if expression and use the local variable inline_data as it is initialized with ext4_has_inline_data(inode) anyway.] Signed-off-by: Tudor Ambarus tudor.ambarus@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/ext4/inode.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1428,7 +1428,8 @@ static int ext4_write_end(struct file *f int inline_data = ext4_has_inline_data(inode);
trace_ext4_write_end(inode, pos, len, copied); - if (inline_data) { + if (inline_data && + ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) { ret = ext4_write_inline_data_end(inode, pos, len, copied, page); if (ret < 0) {