[syzbot] [block?] [udf?] memory leak in __blkdev_issue_zero_pages

From: syzbot

Date: Thu Dec 04 2025 - 10:42:32 EST


Hello,

syzbot found the following issue on:

HEAD commit: 6bda50f4333f Merge tag 'mips-fixes_6.18_2' of git://git.ke..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17ad8192580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f30cc590c4f6da44
dashboard link: https://syzkaller.appspot.com/bug?extid=527a7e48a3d3d315d862
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=10b27cb4580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/864951cecf67/disk-6bda50f4.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/4692a21b76e7/vmlinux-6bda50f4.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a2898beb8301/bzImage-6bda50f4.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/384c8ab49dd6/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+527a7e48a3d3d315d862@xxxxxxxxxxxxxxxxxxxxxxxxx

BUG: memory leak
unreferenced object 0xffff88810dd11b00 (size 200):
comm "syz.3.32", pid 6189, jiffies 4294946488
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 80 70 01 41 81 88 ff ff .........p.A....
01 00 00 00 00 00 00 00 00 00 00 00 01 00 00 00 ................
backtrace (crc fe2a8999):
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]
kmem_cache_alloc_noprof+0x397/0x5a0 mm/slub.c:5295
mempool_alloc_noprof+0xa0/0x200 mm/mempool.c:426
bio_alloc_bioset+0x398/0x7b0 block/bio.c:558
bio_alloc include/linux/bio.h:372 [inline]
__blkdev_issue_zero_pages+0x109/0x2f0 block/blk-lib.c:205
blkdev_issue_zero_pages block/blk-lib.c:239 [inline]
blkdev_issue_zeroout+0x1dc/0x490 block/blk-lib.c:326
blk_ioctl_zeroout block/ioctl.c:250 [inline]
blkdev_common_ioctl+0xb40/0x1180 block/ioctl.c:580
blkdev_ioctl+0x128/0x380 block/ioctl.c:699
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0xf4/0x140 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xa4/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

BUG: memory leak
unreferenced object 0xffff888108a3d000 (size 4096):
comm "syz.3.32", pid 6189, jiffies 4294946488
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace (crc 0):
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]
kmem_cache_alloc_noprof+0x397/0x5a0 mm/slub.c:5295
mempool_alloc_noprof+0xa0/0x200 mm/mempool.c:426
bvec_alloc+0x9d/0x130 block/bio.c:210
bio_alloc_bioset+0x3cb/0x7b0 block/bio.c:573
bio_alloc include/linux/bio.h:372 [inline]
__blkdev_issue_zero_pages+0x109/0x2f0 block/blk-lib.c:205
blkdev_issue_zero_pages block/blk-lib.c:239 [inline]
blkdev_issue_zeroout+0x1dc/0x490 block/blk-lib.c:326
blk_ioctl_zeroout block/ioctl.c:250 [inline]
blkdev_common_ioctl+0xb40/0x1180 block/ioctl.c:580
blkdev_ioctl+0x128/0x380 block/ioctl.c:699
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0xf4/0x140 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xa4/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

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


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