Re: [syzbot] [ext4?] KASAN: use-after-free Read in ext4_find_extent (4)

From: syzbot
Date: Thu Mar 27 2025 - 19:44:18 EST


syzbot has bisected this issue to:

commit 93cdf49f6eca5e23f6546b8f28457b2e6a6961d9
Author: Ojaswin Mujoo <ojaswin@xxxxxxxxxxxxx>
Date: Sat Mar 25 08:13:39 2023 +0000

ext4: Fix best extent lstart adjustment logic in ext4_mb_new_inode_pa()

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1566b43f980000
start commit: 1e1ba8d23dae Merge tag 'timers-clocksource-2025-03-26' of ..
git tree: upstream
final oops: https://syzkaller.appspot.com/x/report.txt?x=1766b43f980000
console output: https://syzkaller.appspot.com/x/log.txt?x=1366b43f980000
kernel config: https://syzkaller.appspot.com/x/.config?x=2edddb53537e0320
dashboard link: https://syzkaller.appspot.com/bug?extid=ee60e584b5c6bb229126
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1623343f980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1123343f980000

Reported-by: syzbot+ee60e584b5c6bb229126@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 93cdf49f6eca ("ext4: Fix best extent lstart adjustment logic in ext4_mb_new_inode_pa()")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection