KASAN: use-after-free Read in gfs2

Kernel	Title	Rank 🛈	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
linux-5.15	KASAN: use-after-free Read in gfs2_invalidatepage	19				1	330d	330d	0/3	auto-obsoleted due to no activity on 2025/03/07 20:25

==================================================================
BUG: KASAN: use-after-free in list_empty include/linux/list.h:290 [inline]
BUG: KASAN: use-after-free in gfs2_discard fs/gfs2/aops.c:656 [inline]
BUG: KASAN: use-after-free in gfs2_invalidatepage+0x4f8/0x830 fs/gfs2/aops.c:693
Read of size 8 at addr ffff88805e6421d8 by task syz-executor/4193

CPU: 0 PID: 4193 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 list_empty include/linux/list.h:290 [inline]
 gfs2_discard fs/gfs2/aops.c:656 [inline]
 gfs2_invalidatepage+0x4f8/0x830 fs/gfs2/aops.c:693
 do_invalidatepage mm/truncate.c:157 [inline]
 truncate_cleanup_page+0x170/0x420 mm/truncate.c:176
 truncate_inode_pages_range+0x236/0xef0 mm/truncate.c:325
 gfs2_evict_inode+0xa81/0x11f0 fs/gfs2/super.c:1415
 evict+0x485/0x870 fs/inode.c:647
 dispose_list fs/inode.c:680 [inline]
 evict_inodes+0x604/0x690 fs/inode.c:734
 generic_shutdown_super+0x93/0x300 fs/super.c:454
 kill_block_super+0x7c/0xe0 fs/super.c:1427
 deactivate_locked_super+0x93/0xf0 fs/super.c:335
 cleanup_mnt+0x418/0x4d0 fs/namespace.c:1139
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 exit_task_work include/linux/task_work.h:33 [inline]
 do_exit+0x61e/0x20a0 kernel/exit.c:883
 do_group_exit+0x12e/0x300 kernel/exit.c:997
 __do_sys_exit_group kernel/exit.c:1008 [inline]
 __se_sys_exit_group kernel/exit.c:1006 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fcb156edec9
Code: Unable to access opcode bytes at RIP 0x7fcb156ede9f.
RSP: 002b:00007ffef75bc0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fcb15770da2 RCX: 00007fcb156edec9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000005 R08: 00007ffef75b9e87 R09: 00007ffef75bd340
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffef75bd340
R13: 00007fcb15770d7d R14: 0000000000012b2e R15: 00007ffef75bd380
 </TASK>

Allocated by task 4319:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0x9c/0xd0 mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3225 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc+0x100/0x290 mm/slub.c:3238
 kmem_cache_zalloc include/linux/slab.h:725 [inline]
 gfs2_alloc_bufdata fs/gfs2/trans.c:168 [inline]
 gfs2_trans_add_data+0x1fd/0x620 fs/gfs2/trans.c:209
 gfs2_page_add_databufs+0x1eb/0x270 fs/gfs2/aops.c:57
 gfs2_iomap_page_done+0xe0/0x180 fs/gfs2/bmap.c:980
 iomap_write_end+0x4e7/0x800 fs/iomap/buffered-io.c:727
 iomap_write_iter fs/iomap/buffered-io.c:775 [inline]
 iomap_file_buffered_write+0x32a/0x5b0 fs/iomap/buffered-io.c:815
 gfs2_file_buffered_write+0x470/0x900 fs/gfs2/file.c:1058
 gfs2_file_write_iter+0x467/0x11d0 fs/gfs2/file.c:1166
 call_write_iter include/linux/fs.h:2172 [inline]
 aio_write+0x513/0x720 fs/aio.c:1594
 __io_submit_one fs/aio.c:-1 [inline]
 io_submit_one+0x6ac/0x1330 fs/aio.c:2013
 __do_sys_io_submit fs/aio.c:2072 [inline]
 __se_sys_io_submit+0x190/0x300 fs/aio.c:2042
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Freed by task 4319:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:46
 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1710 [inline]
 slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736
 slab_free mm/slub.c:3504 [inline]
 kmem_cache_free+0x8f/0x210 mm/slub.c:3520
 trans_drain fs/gfs2/log.c:1015 [inline]
 gfs2_log_flush+0x1995/0x2610 fs/gfs2/log.c:1155
 gfs2_jdata_writepages+0xf5/0x150 fs/gfs2/aops.c:417
 do_writepages+0x48d/0x6d0 mm/page-writeback.c:2386
 filemap_fdatawrite_wbc+0x1eb/0x240 mm/filemap.c:400
 __filemap_fdatawrite_range mm/filemap.c:433 [inline]
 filemap_fdatawrite_range+0xbc/0x100 mm/filemap.c:451
 gfs2_fsync+0xdb/0x340 fs/gfs2/file.c:754
 generic_write_sync include/linux/fs.h:2989 [inline]
 gfs2_file_write_iter+0x60d/0x11d0 fs/gfs2/file.c:1168
 call_write_iter include/linux/fs.h:2172 [inline]
 aio_write+0x513/0x720 fs/aio.c:1594
 __io_submit_one fs/aio.c:-1 [inline]
 io_submit_one+0x6ac/0x1330 fs/aio.c:2013
 __do_sys_io_submit fs/aio.c:2072 [inline]
 __se_sys_io_submit+0x190/0x300 fs/aio.c:2042
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

The buggy address belongs to the object at ffff88805e6421c0
 which belongs to the cache gfs2_bufdata of size 80
The buggy address is located 24 bytes inside of
 80-byte region [ffff88805e6421c0, ffff88805e642210)
The buggy address belongs to the page:
page:ffffea0001799080 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5e642
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 0000000000000000 dead000000000122 ffff88801de15000
raw: 0000000000000000 0000000000240024 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 4319, ts 76452097049, free_ts 76390520699
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192
 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5487
 alloc_slab_page mm/slub.c:1780 [inline]
 allocate_slab mm/slub.c:1917 [inline]
 new_slab+0xc0/0x4b0 mm/slub.c:1980
 ___slab_alloc+0x81e/0xdf0 mm/slub.c:3013
 __slab_alloc mm/slub.c:3100 [inline]
 slab_alloc_node mm/slub.c:3191 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc+0x195/0x290 mm/slub.c:3238
 kmem_cache_zalloc include/linux/slab.h:725 [inline]
 gfs2_alloc_bufdata fs/gfs2/trans.c:168 [inline]
 gfs2_trans_add_meta+0x2ec/0x9e0 fs/gfs2/trans.c:250
 gfs2_indirect_init+0x100/0x480 fs/gfs2/bmap.c:616
 __gfs2_iomap_alloc+0x6e7/0x1a20 fs/gfs2/bmap.c:723
 gfs2_iomap_begin_write fs/gfs2/bmap.c:1049 [inline]
 gfs2_iomap_begin+0xacf/0x1250 fs/gfs2/bmap.c:1114
 iomap_iter+0x620/0xdb0 fs/iomap/iter.c:74
 iomap_file_buffered_write+0x17e/0x5b0 fs/iomap/buffered-io.c:814
 gfs2_file_buffered_write+0x470/0x900 fs/gfs2/file.c:1058
 gfs2_file_write_iter+0x467/0x11d0 fs/gfs2/file.c:1166
 call_write_iter include/linux/fs.h:2172 [inline]
 aio_write+0x513/0x720 fs/aio.c:1594
 __io_submit_one fs/aio.c:-1 [inline]
 io_submit_one+0x6ac/0x1330 fs/aio.c:2013
 __do_sys_io_submit fs/aio.c:2072 [inline]
 __se_sys_io_submit+0x190/0x300 fs/aio.c:2042
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
 free_unref_page_list+0x122/0x7e0 mm/page_alloc.c:3433
 release_pages+0x184b/0x1bb0 mm/swap.c:963
 __pagevec_release+0x6d/0xe0 mm/swap.c:983
 pagevec_release include/linux/pagevec.h:81 [inline]
 __invalidate_mapping_pages+0x4e4/0x5e0 mm/truncate.c:509
 loop_set_status+0x2d1/0x9b0 drivers/block/loop.c:1540
 lo_ioctl+0xc27/0x1cf0 drivers/block/loop.c:-1
 blkdev_ioctl+0x33c/0x690 block/ioctl.c:604
 block_ioctl+0xac/0xf0 block/fops.c:496
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Memory state around the buggy address:
 ffff88805e642080: fb fb fb fb fb fb fb fb fc fc fc fc fa fb fb fb
 ffff88805e642100: fb fb fb fb fb fb fc fc fc fc fa fb fb fb fb fb
>ffff88805e642180: fb fb fb fb fc fc fc fc fa fb fb fb fb fb fb fb
                                                    ^
 ffff88805e642200: fb fb fc fc fc fc fa fb fb fb fb fb fb fb fb fb
 ffff88805e642280: fc fc fc fc fa fb fb fb fb fb fb fb fb fb fc fc
==================================================================

Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Assets (help?)	Manager	Title
2025/10/11 00:49	linux-5.15.y	29e53a5b1c4f	ff1712fe	.config	console log	report	info	[disk image] [vmlinux] [kernel image]	ci2-linux-5-15-kasan	KASAN: use-after-free Read in gfs2_invalidatepage
2025/07/30 07:29	linux-5.15.y	c79648372d02	f8f2b4da	.config	console log	report	info	[disk image] [vmlinux] [kernel image]	ci2-linux-5-15-kasan	KASAN: use-after-free Read in gfs2_invalidatepage
2025/07/21 11:30	linux-5.15.y	c79648372d02	56d87229	.config	console log	report	info	[disk image] [vmlinux] [kernel image]	ci2-linux-5-15-kasan-arm64	KASAN: use-after-free Read in gfs2_invalidatepage
2025/06/20 10:19	linux-5.15.y	1c700860e8bc	ed3e87f7	.config	console log	report	info	[disk image] [vmlinux] [kernel image]	ci2-linux-5-15-kasan-arm64	KASAN: use-after-free Read in gfs2_invalidatepage
2025/05/14 06:37	linux-5.15.y	3b8db0e4f263	7344edeb	.config	console log	report	info	[disk image] [vmlinux] [kernel image]	ci2-linux-5-15-kasan-arm64	KASAN: use-after-free Read in gfs2_invalidatepage