linux-kernel - Re: [syzbot] [ocfs2?] memory leak in ocfs2_new_path_from

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Message-ID: <692f433e.a70a0220.d98e3.01a3.GAE@google.com>
Date: Tue, 02 Dec 2025 11:51:26 -0800
From: syzbot <syzbot+cfc7cab3bb6eaa7c4de2@...kaller.appspotmail.com>
To: akpm@...ux-foundation.org, david.hunter.linux@...il.com, david@...hat.com, 
	dsterba@...e.com, jfs-discussion@...ts.sourceforge.net, jlbec@...lplan.org, 
	joseph.qi@...ux.alibaba.com, khalid@...nel.org, 
	linux-kernel-mentees@...ts.linux.dev, linux-kernel@...r.kernel.org, 
	mark@...heh.com, ocfs2-devel@...ts.linux.dev, 
	penguin-kernel@...ove.sakura.ne.jp, shaggy@...nel.org, shivankg@....com, 
	skhan@...uxfoundation.org, ssrane_b23@...vjti.ac.in, 
	syzkaller-bugs@...glegroups.com
Subject: Re: [syzbot] [ocfs2?] memory leak in ocfs2_new_path_from_path

syzbot has found a reproducer for the following issue on:

HEAD commit:    4a26e7032d7d Merge tag 'core-bugs-2025-12-01' of git://git..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=111c14c2580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=cbf343972ee89096
dashboard link: https://syzkaller.appspot.com/bug?extid=cfc7cab3bb6eaa7c4de2
compiler:       gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16833512580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=151c14c2580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/3f4ff8b7d65f/disk-4a26e703.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/2fbb585ef1ac/vmlinux-4a26e703.xz
kernel image: https://storage.googleapis.com/syzbot-assets/dfdc58db78d3/bzImage-4a26e703.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/ef2db83daf44/mount_0.gz
  fsck result: OK (log: https://syzkaller.appspot.com/x/fsck.log?x=14cae192580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+cfc7cab3bb6eaa7c4de2@...kaller.appspotmail.com

BUG: memory leak
unreferenced object 0xffff8881292668a0 (size 96):
  comm "syz.1.52", pid 6365, jiffies 4294945684
  hex dump (first 32 bytes):
    01 00 00 00 00 00 00 00 80 0e 31 82 ff ff ff ff  ..........1.....
    50 e7 58 27 81 88 ff ff c0 54 eb 33 81 88 ff ff  P.X'.....T.3....
  backtrace (crc d3d62878):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4983 [inline]
    slab_alloc_node mm/slub.c:5288 [inline]
    __kmalloc_cache_noprof+0x3a6/0x5b0 mm/slub.c:5766
    kmalloc_noprof include/linux/slab.h:957 [inline]
    kzalloc_noprof include/linux/slab.h:1094 [inline]
    ocfs2_new_path fs/ocfs2/alloc.c:688 [inline]
    ocfs2_new_path_from_path+0x4f/0x90 fs/ocfs2/alloc.c:702
    ocfs2_get_left_path.constprop.0+0x182/0x390 fs/ocfs2/alloc.c:3491
    ocfs2_merge_rec_left+0x426/0xe60 fs/ocfs2/alloc.c:3543
    ocfs2_try_to_merge_extent+0x3cb/0xe90 fs/ocfs2/alloc.c:3794
    ocfs2_split_extent+0xd2e/0x1330 fs/ocfs2/alloc.c:5139
    ocfs2_change_extent_flag+0x2ed/0x720 fs/ocfs2/alloc.c:5230
    ocfs2_mark_extent_written+0x1e3/0x2c0 fs/ocfs2/alloc.c:5276
    ocfs2_dio_end_io_write+0x5bc/0xaa0 fs/ocfs2/aops.c:2350
    ocfs2_dio_end_io+0x8c/0x180 fs/ocfs2/aops.c:2404
    dio_complete+0x12e/0x4b0 fs/direct-io.c:281
    __blockdev_direct_IO+0x1782/0x1b40 fs/direct-io.c:1303
    ocfs2_direct_IO+0xf6/0x100 fs/ocfs2/aops.c:2441
    generic_file_direct_write+0xb4/0x180 mm/filemap.c:4234
    __generic_file_write_iter+0xa1/0x130 mm/filemap.c:4403
    ocfs2_file_write_iter+0x68a/0x15a0 fs/ocfs2/file.c:2469

connection error: failed to recv *flatrpc.ExecutorMessageRawT: EOF


---
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.