Mark Tinguely 1d3c96547e ocfs2: fix recursive semaphore deadlock in fiemap call ... commit 04100f775c upstream. syzbot detected a OCFS2 hang due to a recursive semaphore on a FS_IOC_FIEMAP of the extent list on a specially crafted mmap file. context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 rwsem_down_write_slowpath+0x872/0xfe0 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1591 ocfs2_page_mkwrite+0x2ff/0xc40 fs/ocfs2/mmap.c:142 do_page_mkwrite+0x14d/0x310 mm/memory.c:3361 wp_page_shared mm/memory.c:3762 [inline] do_wp_page+0x268d/0x5800 mm/memory.c:3981 handle_pte_fault mm/memory.c:6068 [inline] __handle_mm_fault+0x1033/0x5440 mm/memory.c:6195 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6364 do_user_addr_fault+0x764/0x1390 arch/x86/mm/fault.c:1387 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0010:copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline] RIP: 0010:raw_copy_to_user arch/x86/include/asm/uaccess_64.h:147 [inline] RIP: 0010:_inline_copy_to_user include/linux/uaccess.h:197 [inline] RIP: 0010:_copy_to_user+0x85/0xb0 lib/usercopy.c:26 Code: e8 00 bc f7 fc 4d 39 fc 72 3d 4d 39 ec 77 38 e8 91 b9 f7 fc 4c 89 f7 89 de e8 47 25 5b fd 0f 01 cb 4c 89 ff 48 89 d9 4c 89 f6 <f3> a4 0f 1f 00 48 89 cb 0f 01 ca 48 89 d8 5b 41 5c 41 5d 41 5e 41 RSP: 0018:ffffc9000403f950 EFLAGS: 00050256 RAX: ffffffff84c7f101 RBX: 0000000000000038 RCX: 0000000000000038 RDX: 0000000000000000 RSI: ffffc9000403f9e0 RDI: 0000200000000060 RBP: ffffc9000403fa90 R08: ffffc9000403fa17 R09: 1ffff92000807f42 R10: dffffc0000000000 R11: fffff52000807f43 R12: 0000200000000098 R13: 00007ffffffff000 R14: ffffc9000403f9e0 R15: 0000200000000060 copy_to_user include/linux/uaccess.h:225 [inline] fiemap_fill_next_extent+0x1c0/0x390 fs/ioctl.c:145 ocfs2_fiemap+0x888/0xc90 fs/ocfs2/extent_map.c:806 ioctl_fiemap fs/ioctl.c:220 [inline] do_vfs_ioctl+0x1173/0x1430 fs/ioctl.c:532 __do_sys_ioctl fs/ioctl.c:596 [inline] __se_sys_ioctl+0x82/0x170 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5f13850fd9 RSP: 002b:00007ffe3b3518b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000200000000000 RCX: 00007f5f13850fd9 RDX: 0000200000000040 RSI: 00000000c020660b RDI: 0000000000000004 RBP: 6165627472616568 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe3b3518f0 R13: 00007ffe3b351b18 R14: 431bde82d7b634db R15: 00007f5f1389a03b ocfs2_fiemap() takes a read lock of the ip_alloc_sem semaphore (since v2.6.22-527-g7307de80510a) and calls fiemap_fill_next_extent() to read the extent list of this running mmap executable. The user supplied buffer to hold the fiemap information page faults calling ocfs2_page_mkwrite() which will take a write lock (since v2.6.27-38-g00dc417fa3e7) of the same semaphore. This recursive semaphore will hold filesystem locks and causes a hang of the fileystem. The ip_alloc_sem protects the inode extent list and size. Release the read semphore before calling fiemap_fill_next_extent() in ocfs2_fiemap() and ocfs2_fiemap_inline(). This does an unnecessary semaphore lock/unlock on the last extent but simplifies the error path. Link: https://lkml.kernel.org/r/61d1a62b-2631-4f12-81e2-cd689914360b@oracle.com Fixes: 00dc417fa3 ("ocfs2: fiemap support") Signed-off-by: Mark Tinguely <mark.tinguely@oracle.com> Reported-by: syzbot+541dcc6ee768f77103e7@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=541dcc6ee768f77103e7 Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Jun Piao <piaojun@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2025-09-19 16:35:45 +02:00
..
cluster	…
dlm	…
dlmfs	…
Kconfig	…
Makefile	…
acl.c	…
acl.h	…
alloc.c	ocfs2: validate l_tree_depth to avoid out-of-bounds access	2025-04-10 14:39:24 +02:00
alloc.h	…
aops.c	…
aops.h	ocfs2: fix uninitialized value in ocfs2_file_read_iter()	2024-12-05 14:02:13 +01:00
blockcheck.c	…
blockcheck.h	…
buffer_head_io.c	…
buffer_head_io.h	…
dcache.c	…
dcache.h	…
dir.c	ocfs2: check dir i_size in ocfs2_find_entry	2025-02-17 10:05:48 +01:00
dir.h	…
dlmglue.c	ocfs2: update seq_file index in ocfs2_dlm_seq_next	2024-12-14 20:03:31 +01:00
dlmglue.h	…
export.c	…
export.h	…
extent_map.c	ocfs2: fix recursive semaphore deadlock in fiemap call	2025-09-19 16:35:45 +02:00
extent_map.h	…
file.c	ocfs2: fix uninitialized value in ocfs2_file_read_iter()	2024-12-05 14:02:13 +01:00
file.h	…
filecheck.c	…
filecheck.h	…
heartbeat.c	…
heartbeat.h	…
inode.c	ocfs2: prevent release journal inode after journal shutdown	2025-09-09 18:58:16 +02:00
inode.h	…
ioctl.c	…
ioctl.h	…
journal.c	fs/ocfs2: use sleeping version of __find_get_block()	2025-05-29 11:02:00 +02:00
journal.h	ocfs2: stop quota recovery before disabling quotas	2025-05-18 08:24:54 +02:00
localalloc.c	ocfs2: fix the space leak in LA when releasing LA	2024-12-27 14:02:18 +01:00
localalloc.h	…
locks.c	…
locks.h	…
mmap.c	…
mmap.h	…
move_extents.c	…
move_extents.h	…
namei.c	ocfs2: free inode when ocfs2_get_init_inode() fails	2024-12-14 20:03:18 +01:00
namei.h	…
ocfs1_fs_compat.h	…
ocfs2.h	ocfs2: stop quota recovery before disabling quotas	2025-05-18 08:24:54 +02:00
ocfs2_fs.h	…
ocfs2_ioctl.h	…
ocfs2_lockid.h	…
ocfs2_lockingver.h	…
ocfs2_trace.h	…
quota.h	…
quota_global.c	ocfs2: mark dquot as inactive if failed to start trans while releasing dquot	2025-02-08 09:57:58 +01:00
quota_local.c	ocfs2: fix possible memory leak in ocfs2_finish_quota_recovery	2025-06-19 15:32:01 +02:00
refcounttree.c	…
refcounttree.h	…
reservations.c	…
reservations.h	…
resize.c	ocfs2: uncache inode which has failed entering the group	2024-11-14 22:43:48 -08:00
resize.h	…
slot_map.c	…
slot_map.h	…
stack_o2cb.c	…
stack_user.c	…
stackglue.c	…
stackglue.h	…
suballoc.c	ocfs2: fix the issue with discontiguous allocation in the global_bitmap	2025-05-18 08:24:54 +02:00
suballoc.h	ocfs2: fix the issue with discontiguous allocation in the global_bitmap	2025-05-18 08:24:54 +02:00
super.c	ocfs2: stop quota recovery before disabling quotas	2025-05-18 08:24:54 +02:00
super.h	…
symlink.c	ocfs2: handle a symlink read error correctly	2025-02-17 10:05:39 +01:00
symlink.h	…
sysfile.c	…
sysfile.h	…
uptodate.c	…
uptodate.h	…
xattr.c	ocfs2: remove entry once instead of null-ptr-dereference in ocfs2_xa_remove()	2024-11-07 14:14:59 -08:00
xattr.h	…