This reverts commit 60263d5889e6dc5987dc51b801be4955ff2e4aa7. Reverting since this commit opens a potential avenue for abuse. The C-reproducer and more information can be found at the link below. With this patch applied, I can no longer get the repro to trigger. kernel BUG at fs/ext4/inode.c:2647! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 459 Comm: syz-executor359 Tainted: G W 5.10.93-syzkaller-01028-g0347b1658399 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:mpage_prepare_extent_to_map+0xbe9/0xc00 fs/ext4/inode.c:2647 Code: e8 fc bd c3 ff e9 80 f6 ff ff 44 89 e9 80 e1 07 38 c1 0f 8c a6 fe ff ff 4c 89 ef e8 e1 bd c3 ff e9 99 fe ff ff e8 87 c9 89 ff <0f> 0b e8 80 c9 89 ff 0f 0b e8 79 1e b8 02 66 0f 1f 84 00 00 00 00 RSP: 0018:ffffc90000e2e9c0 EFLAGS: 00010293 RAX: ffffffff81e321f9 RBX: 0000000000000000 RCX: ffff88810c12cf00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000e2eb90 R08: ffffffff81e31e71 R09: fffff940008d68b1 R10: fffff940008d68b1 R11: 0000000000000000 R12: ffffea00046b4580 R13: ffffc90000e2ea80 R14: 000000000000011e R15: dffffc0000000000 FS: 00007fcfd0717700(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcfd07d5520 CR3: 000000010a142000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ext4_writepages+0xcbb/0x3950 fs/ext4/inode.c:2776 do_writepages+0x13a/0x280 mm/page-writeback.c:2358 __filemap_fdatawrite_range+0x356/0x420 mm/filemap.c:427 filemap_write_and_wait_range+0x64/0xe0 mm/filemap.c:660 __iomap_dio_rw+0x621/0x10c0 fs/iomap/direct-io.c:495 iomap_dio_rw+0x35/0x80 fs/iomap/direct-io.c:611 ext4_dio_write_iter fs/ext4/file.c:571 [inline] ext4_file_write_iter+0xfc5/0x1b70 fs/ext4/file.c:681 do_iter_readv_writev+0x548/0x740 include/linux/fs.h:1941 do_iter_write+0x182/0x660 fs/read_write.c:866 vfs_iter_write+0x7c/0xa0 fs/read_write.c:907 iter_file_splice_write+0x7fb/0xf70 fs/splice.c:686 do_splice_from fs/splice.c:764 [inline] direct_splice_actor+0xfe/0x130 fs/splice.c:933 splice_direct_to_actor+0x4f4/0xbc0 fs/splice.c:888 do_splice_direct+0x28b/0x3e0 fs/splice.c:976 do_sendfile+0x914/0x1390 fs/read_write.c:1257 Link: https://syzkaller.appspot.com/bug?extid=41c966bf0729a530bd8d
