[PATCH AUTOSEL 6.11 11/76] ext4: fix i_data_sem unlock order in ext4_ind_migrate()

[PATCH AUTOSEL 6.11 11/76] ext4: fix i_data_sem unlock order in ext4_ind_migrate()

[Sasha Levin]

From: Artem Sadovnikov <ancowi69@gmail.com>

[ Upstream commit cc749e61c011c255d81b192a822db650c68b313f ]

Fuzzing reports a possible deadlock in jbd2_log_wait_commit.

This issue is triggered when an EXT4_IOC_MIGRATE ioctl is set to require
synchronous updates because the file descriptor is opened with O_SYNC.
This can lead to the jbd2_journal_stop() function calling
jbd2_might_wait_for_commit(), potentially causing a deadlock if the
EXT4_IOC_MIGRATE call races with a write(2) system call.

This problem only arises when CONFIG_PROVE_LOCKING is enabled. In this
case, the jbd2_might_wait_for_commit macro locks jbd2_handle in the
jbd2_journal_stop function while i_data_sem is locked. This triggers
lockdep because the jbd2_journal_start function might also lock the same
jbd2_handle simultaneously.

Found by Linux Verification Center (linuxtesting.org) with syzkaller.

Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Co-developed-by: Mikhail Ukhin <mish.uxin2012@yandex.ru>
Signed-off-by: Mikhail Ukhin <mish.uxin2012@yandex.ru>
Signed-off-by: Artem Sadovnikov <ancowi69@gmail.com>
Rule: add
Link: https://lore.kernel.org/stable/20240404095000.5872-1-mish.uxin2012%40yandex.ru
Link: https://patch.msgid.link/20240829152210.2754-1-ancowi69@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ext4/migrate.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c
index d98ac2af8199f..a5e1492bbaaa5 100644
--- a/fs/ext4/migrate.c
+++ b/fs/ext4/migrate.c
@@ -663,8 +663,8 @@ int ext4_ind_migrate(struct inode *inode)
 	if (unlikely(ret2 && !ret))
 		ret = ret2;
 errout:
-	ext4_journal_stop(handle);
 	up_write(&EXT4_I(inode)->i_data_sem);
+	ext4_journal_stop(handle);
 out_unlock:
 	ext4_writepages_up_write(inode->i_sb, alloc_ctx);
 	return ret;
-- 
2.43.0

[PATCH AUTOSEL 6.11 12/76] ext4: avoid use-after-free in ext4_ext_show_leaf()

[Sasha Levin]

From: Baokun Li <libaokun1@huawei.com>

[ Upstream commit 4e2524ba2ca5f54bdbb9e5153bea00421ef653f5 ]

In ext4_find_extent(), path may be freed by error or be reallocated, so
using a previously saved *ppath may have been freed and thus may trigger
use-after-free, as follows:

ext4_split_extent
  path = *ppath;
  ext4_split_extent_at(ppath)
  path = ext4_find_extent(ppath)
  ext4_split_extent_at(ppath)
    // ext4_find_extent fails to free path
    // but zeroout succeeds
  ext4_ext_show_leaf(inode, path)
    eh = path[depth].p_hdr
    // path use-after-free !!!

Similar to ext4_split_extent_at(), we use *ppath directly as an input to
ext4_ext_show_leaf(). Fix a spelling error by the way.

Same problem in ext4_ext_handle_unwritten_extents(). Since 'path' is only
used in ext4_ext_show_leaf(), remove 'path' and use *ppath directly.

This issue is triggered only when EXT_DEBUG is defined and therefore does
not affect functionality.

Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Tested-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/20240822023545.1994557-5-libaokun@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ext4/extents.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index e067f2dd0335c..7954430f886d8 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3287,7 +3287,7 @@ static int ext4_split_extent_at(handle_t *handle,
 }
 
 /*
- * ext4_split_extents() splits an extent and mark extent which is covered
+ * ext4_split_extent() splits an extent and mark extent which is covered
  * by @map as split_flags indicates
  *
  * It may result in splitting the extent into multiple extents (up to three)
@@ -3363,7 +3363,7 @@ static int ext4_split_extent(handle_t *handle,
 			goto out;
 	}
 
-	ext4_ext_show_leaf(inode, path);
+	ext4_ext_show_leaf(inode, *ppath);
 out:
 	return err ? err : allocated;
 }
@@ -3828,14 +3828,13 @@ ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode,
 			struct ext4_ext_path **ppath, int flags,
 			unsigned int allocated, ext4_fsblk_t newblock)
 {
-	struct ext4_ext_path __maybe_unused *path = *ppath;
 	int ret = 0;
 	int err = 0;
 
 	ext_debug(inode, "logical block %llu, max_blocks %u, flags 0x%x, allocated %u\n",
 		  (unsigned long long)map->m_lblk, map->m_len, flags,
 		  allocated);
-	ext4_ext_show_leaf(inode, path);
+	ext4_ext_show_leaf(inode, *ppath);
 
 	/*
 	 * When writing into unwritten space, we should not fail to
@@ -3932,7 +3931,7 @@ ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode,
 	if (allocated > map->m_len)
 		allocated = map->m_len;
 	map->m_len = allocated;
-	ext4_ext_show_leaf(inode, path);
+	ext4_ext_show_leaf(inode, *ppath);
 out2:
 	return err ? err : allocated;
 }
-- 
2.43.0

[PATCH AUTOSEL 6.11 13/76] ext4: ext4_search_dir should return a proper error

[Sasha Levin]

From: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>

[ Upstream commit cd69f8f9de280e331c9e6ff689ced0a688a9ce8f ]

ext4_search_dir currently returns -1 in case of a failure, while it returns
0 when the name is not found. In such failure cases, it should return an
error code instead.

This becomes even more important when ext4_find_inline_entry returns an
error code as well in the next commit.

-EFSCORRUPTED seems appropriate as such error code as these failures would
be caused by unexpected record lengths and is in line with other instances
of ext4_check_dir_entry failures.

In the case of ext4_dx_find_entry, the current use of ERR_BAD_DX_DIR was
left as is to reduce the risk of regressions.

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Link: https://patch.msgid.link/20240821152324.3621860-2-cascardo@igalia.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ext4/namei.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 6a95713f9193b..8af437ac30511 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1482,7 +1482,7 @@ static bool ext4_match(struct inode *parent,
 }
 
 /*
- * Returns 0 if not found, -1 on failure, and 1 on success
+ * Returns 0 if not found, -EFSCORRUPTED on failure, and 1 on success
  */
 int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
 		    struct inode *dir, struct ext4_filename *fname,
@@ -1503,7 +1503,7 @@ int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
 			 * a full check */
 			if (ext4_check_dir_entry(dir, NULL, de, bh, search_buf,
 						 buf_size, offset))
-				return -1;
+				return -EFSCORRUPTED;
 			*res_dir = de;
 			return 1;
 		}
@@ -1511,7 +1511,7 @@ int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
 		de_len = ext4_rec_len_from_disk(de->rec_len,
 						dir->i_sb->s_blocksize);
 		if (de_len <= 0)
-			return -1;
+			return -EFSCORRUPTED;
 		offset += de_len;
 		de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
 	}
@@ -1663,8 +1663,10 @@ static struct buffer_head *__ext4_find_entry(struct inode *dir,
 			goto cleanup_and_exit;
 		} else {
 			brelse(bh);
-			if (i < 0)
+			if (i < 0) {
+				ret = ERR_PTR(i);
 				goto cleanup_and_exit;
+			}
 		}
 	next:
 		if (++block >= nblocks)
@@ -1758,7 +1760,7 @@ static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
 		if (retval == 1)
 			goto success;
 		brelse(bh);
-		if (retval == -1) {
+		if (retval < 0) {
 			bh = ERR_PTR(ERR_BAD_DX_DIR);
 			goto errout;
 		}
-- 
2.43.0

[PATCH AUTOSEL 6.11 15/76] ext4: don't set SB_RDONLY after filesystem errors

[Sasha Levin]

From: Jan Kara <jack@suse.cz>

[ Upstream commit d3476f3dad4ad68ae5f6b008ea6591d1520da5d8 ]

When the filesystem is mounted with errors=remount-ro, we were setting
SB_RDONLY flag to stop all filesystem modifications. We knew this misses
proper locking (sb->s_umount) and does not go through proper filesystem
remount procedure but it has been the way this worked since early ext2
days and it was good enough for catastrophic situation damage
mitigation. Recently, syzbot has found a way (see link) to trigger
warnings in filesystem freezing because the code got confused by
SB_RDONLY changing under its hands. Since these days we set
EXT4_FLAGS_SHUTDOWN on the superblock which is enough to stop all
filesystem modifications, modifying SB_RDONLY shouldn't be needed. So
stop doing that.

Link: https://lore.kernel.org/all/000000000000b90a8e061e21d12f@google.com
Reported-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Link: https://patch.msgid.link/20240805201241.27286-1-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ext4/super.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index e72145c4ae5a0..93c016b186c07 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -735,11 +735,12 @@ static void ext4_handle_error(struct super_block *sb, bool force_ro, int error,
 
 	ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 	/*
-	 * Make sure updated value of ->s_mount_flags will be visible before
-	 * ->s_flags update
+	 * EXT4_FLAGS_SHUTDOWN was set which stops all filesystem
+	 * modifications. We don't set SB_RDONLY because that requires
+	 * sb->s_umount semaphore and setting it without proper remount
+	 * procedure is confusing code such as freeze_super() leading to
+	 * deadlocks and other problems.
 	 */
-	smp_wmb();
-	sb->s_flags |= SB_RDONLY;
 }
 
 static void update_super_work(struct work_struct *work)
-- 
2.43.0

[PATCH AUTOSEL 6.11 16/76] ext4: nested locking for xattr inode

[Sasha Levin]

From: Wojciech Gładysz <wojciech.gladysz@infogain.com>

[ Upstream commit d1bc560e9a9c78d0b2314692847fc8661e0aeb99 ]

Add nested locking with I_MUTEX_XATTR subclass to avoid lockdep warning
while handling xattr inode on file open syscall at ext4_xattr_inode_iget.

Backtrace
EXT4-fs (loop0): Ignoring removed oldalloc option
======================================================
WARNING: possible circular locking dependency detected
5.10.0-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor543/2794 is trying to acquire lock:
ffff8880215e1a48 (&ea_inode->i_rwsem#7/1){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:782 [inline]
ffff8880215e1a48 (&ea_inode->i_rwsem#7/1){+.+.}-{3:3}, at: ext4_xattr_inode_iget+0x42a/0x5c0 fs/ext4/xattr.c:425

but task is already holding lock:
ffff8880215e3278 (&ei->i_data_sem/3){++++}-{3:3}, at: ext4_setattr+0x136d/0x19c0 fs/ext4/inode.c:5559

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&ei->i_data_sem/3){++++}-{3:3}:
       lock_acquire+0x197/0x480 kernel/locking/lockdep.c:5566
       down_write+0x93/0x180 kernel/locking/rwsem.c:1564
       ext4_update_i_disksize fs/ext4/ext4.h:3267 [inline]
       ext4_xattr_inode_write fs/ext4/xattr.c:1390 [inline]
       ext4_xattr_inode_lookup_create fs/ext4/xattr.c:1538 [inline]
       ext4_xattr_set_entry+0x331a/0x3d80 fs/ext4/xattr.c:1662
       ext4_xattr_ibody_set+0x124/0x390 fs/ext4/xattr.c:2228
       ext4_xattr_set_handle+0xc27/0x14e0 fs/ext4/xattr.c:2385
       ext4_xattr_set+0x219/0x390 fs/ext4/xattr.c:2498
       ext4_xattr_user_set+0xc9/0xf0 fs/ext4/xattr_user.c:40
       __vfs_setxattr+0x404/0x450 fs/xattr.c:177
       __vfs_setxattr_noperm+0x11d/0x4f0 fs/xattr.c:208
       __vfs_setxattr_locked+0x1f9/0x210 fs/xattr.c:266
       vfs_setxattr+0x112/0x2c0 fs/xattr.c:283
       setxattr+0x1db/0x3e0 fs/xattr.c:548
       path_setxattr+0x15a/0x240 fs/xattr.c:567
       __do_sys_setxattr fs/xattr.c:582 [inline]
       __se_sys_setxattr fs/xattr.c:578 [inline]
       __x64_sys_setxattr+0xc5/0xe0 fs/xattr.c:578
       do_syscall_64+0x6d/0xa0 arch/x86/entry/common.c:62
       entry_SYSCALL_64_after_hwframe+0x61/0xcb

-> #0 (&ea_inode->i_rwsem#7/1){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:2988 [inline]
       check_prevs_add kernel/locking/lockdep.c:3113 [inline]
       validate_chain+0x1695/0x58f0 kernel/locking/lockdep.c:3729
       __lock_acquire+0x12fd/0x20d0 kernel/locking/lockdep.c:4955
       lock_acquire+0x197/0x480 kernel/locking/lockdep.c:5566
       down_write+0x93/0x180 kernel/locking/rwsem.c:1564
       inode_lock include/linux/fs.h:782 [inline]
       ext4_xattr_inode_iget+0x42a/0x5c0 fs/ext4/xattr.c:425
       ext4_xattr_inode_get+0x138/0x410 fs/ext4/xattr.c:485
       ext4_xattr_move_to_block fs/ext4/xattr.c:2580 [inline]
       ext4_xattr_make_inode_space fs/ext4/xattr.c:2682 [inline]
       ext4_expand_extra_isize_ea+0xe70/0x1bb0 fs/ext4/xattr.c:2774
       __ext4_expand_extra_isize+0x304/0x3f0 fs/ext4/inode.c:5898
       ext4_try_to_expand_extra_isize fs/ext4/inode.c:5941 [inline]
       __ext4_mark_inode_dirty+0x591/0x810 fs/ext4/inode.c:6018
       ext4_setattr+0x1400/0x19c0 fs/ext4/inode.c:5562
       notify_change+0xbb6/0xe60 fs/attr.c:435
       do_truncate+0x1de/0x2c0 fs/open.c:64
       handle_truncate fs/namei.c:2970 [inline]
       do_open fs/namei.c:3311 [inline]
       path_openat+0x29f3/0x3290 fs/namei.c:3425
       do_filp_open+0x20b/0x450 fs/namei.c:3452
       do_sys_openat2+0x124/0x460 fs/open.c:1207
       do_sys_open fs/open.c:1223 [inline]
       __do_sys_open fs/open.c:1231 [inline]
       __se_sys_open fs/open.c:1227 [inline]
       __x64_sys_open+0x221/0x270 fs/open.c:1227
       do_syscall_64+0x6d/0xa0 arch/x86/entry/common.c:62
       entry_SYSCALL_64_after_hwframe+0x61/0xcb

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ei->i_data_sem/3);
                               lock(&ea_inode->i_rwsem#7/1);
                               lock(&ei->i_data_sem/3);
  lock(&ea_inode->i_rwsem#7/1);

 *** DEADLOCK ***

5 locks held by syz-executor543/2794:
 #0: ffff888026fbc448 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x4a/0x2a0 fs/namespace.c:365
 #1: ffff8880215e3488 (&sb->s_type->i_mutex_key#7){++++}-{3:3}, at: inode_lock include/linux/fs.h:782 [inline]
 #1: ffff8880215e3488 (&sb->s_type->i_mutex_key#7){++++}-{3:3}, at: do_truncate+0x1cf/0x2c0 fs/open.c:62
 #2: ffff8880215e3310 (&ei->i_mmap_sem){++++}-{3:3}, at: ext4_setattr+0xec4/0x19c0 fs/ext4/inode.c:5519
 #3: ffff8880215e3278 (&ei->i_data_sem/3){++++}-{3:3}, at: ext4_setattr+0x136d/0x19c0 fs/ext4/inode.c:5559
 #4: ffff8880215e30c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:162 [inline]
 #4: ffff8880215e30c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:5938 [inline]
 #4: ffff8880215e30c8 (&ei->xattr_sem){++++}-{3:3}, at: __ext4_mark_inode_dirty+0x4fb/0x810 fs/ext4/inode.c:6018

stack backtrace:
CPU: 1 PID: 2794 Comm: syz-executor543 Not tainted 5.10.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x177/0x211 lib/dump_stack.c:118
 print_circular_bug+0x146/0x1b0 kernel/locking/lockdep.c:2002
 check_noncircular+0x2cc/0x390 kernel/locking/lockdep.c:2123
 check_prev_add kernel/locking/lockdep.c:2988 [inline]
 check_prevs_add kernel/locking/lockdep.c:3113 [inline]
 validate_chain+0x1695/0x58f0 kernel/locking/lockdep.c:3729
 __lock_acquire+0x12fd/0x20d0 kernel/locking/lockdep.c:4955
 lock_acquire+0x197/0x480 kernel/locking/lockdep.c:5566
 down_write+0x93/0x180 kernel/locking/rwsem.c:1564
 inode_lock include/linux/fs.h:782 [inline]
 ext4_xattr_inode_iget+0x42a/0x5c0 fs/ext4/xattr.c:425
 ext4_xattr_inode_get+0x138/0x410 fs/ext4/xattr.c:485
 ext4_xattr_move_to_block fs/ext4/xattr.c:2580 [inline]
 ext4_xattr_make_inode_space fs/ext4/xattr.c:2682 [inline]
 ext4_expand_extra_isize_ea+0xe70/0x1bb0 fs/ext4/xattr.c:2774
 __ext4_expand_extra_isize+0x304/0x3f0 fs/ext4/inode.c:5898
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:5941 [inline]
 __ext4_mark_inode_dirty+0x591/0x810 fs/ext4/inode.c:6018
 ext4_setattr+0x1400/0x19c0 fs/ext4/inode.c:5562
 notify_change+0xbb6/0xe60 fs/attr.c:435
 do_truncate+0x1de/0x2c0 fs/open.c:64
 handle_truncate fs/namei.c:2970 [inline]
 do_open fs/namei.c:3311 [inline]
 path_openat+0x29f3/0x3290 fs/namei.c:3425
 do_filp_open+0x20b/0x450 fs/namei.c:3452
 do_sys_openat2+0x124/0x460 fs/open.c:1207
 do_sys_open fs/open.c:1223 [inline]
 __do_sys_open fs/open.c:1231 [inline]
 __se_sys_open fs/open.c:1227 [inline]
 __x64_sys_open+0x221/0x270 fs/open.c:1227
 do_syscall_64+0x6d/0xa0 arch/x86/entry/common.c:62
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f0cde4ea229
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 21 18 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd81d1c978 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0030656c69662f30 RCX: 00007f0cde4ea229
RDX: 0000000000000089 RSI: 00000000000a0a00 RDI: 00000000200001c0
RBP: 2f30656c69662f2e R08: 0000000000208000 R09: 0000000000208000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd81d1c9c0
R13: 00007ffd81d1ca00 R14: 0000000000080000 R15: 0000000000000003
EXT4-fs error (device loop0): ext4_expand_extra_isize_ea:2730: inode #13: comm syz-executor543: corrupted in-inode xattr

Signed-off-by: Wojciech Gładysz <wojciech.gladysz@infogain.com>
Link: https://patch.msgid.link/20240801143827.19135-1-wojciech.gladysz@infogain.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ext4/xattr.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 46ce2f21fef9d..a6bc9a22a8afc 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -458,7 +458,7 @@ static int ext4_xattr_inode_iget(struct inode *parent, unsigned long ea_ino,
 		ext4_set_inode_state(inode, EXT4_STATE_LUSTRE_EA_INODE);
 		ext4_xattr_inode_set_ref(inode, 1);
 	} else {
-		inode_lock(inode);
+		inode_lock_nested(inode, I_MUTEX_XATTR);
 		inode->i_flags |= S_NOQUOTA;
 		inode_unlock(inode);
 	}
@@ -1039,7 +1039,7 @@ static int ext4_xattr_inode_update_ref(handle_t *handle, struct inode *ea_inode,
 	s64 ref_count;
 	int ret;
 
-	inode_lock(ea_inode);
+	inode_lock_nested(ea_inode, I_MUTEX_XATTR);
 
 	ret = ext4_reserve_inode_write(handle, ea_inode, &iloc);
 	if (ret)
-- 
2.43.0

[PATCH AUTOSEL 6.11 18/76] ext4: filesystems without casefold feature cannot be mounted with siphash

[Sasha Levin]

From: Lizhi Xu <lizhi.xu@windriver.com>

[ Upstream commit 985b67cd86392310d9e9326de941c22fc9340eec ]

When mounting the ext4 filesystem, if the default hash version is set to
DX_HASH_SIPHASH but the casefold feature is not set, exit the mounting.

Reported-by: syzbot+340581ba9dceb7e06fb3@syzkaller.appspotmail.com
Signed-off-by: Lizhi Xu <lizhi.xu@windriver.com>
Link: https://patch.msgid.link/20240605012335.44086-1-lizhi.xu@windriver.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ext4/super.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 93c016b186c07..e8e32cf3e2228 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3583,6 +3583,13 @@ int ext4_feature_set_ok(struct super_block *sb, int readonly)
 			 "mounted without CONFIG_UNICODE");
 		return 0;
 	}
+	if (EXT4_SB(sb)->s_es->s_def_hash_version == DX_HASH_SIPHASH &&
+	    !ext4_has_feature_casefold(sb)) {
+		ext4_msg(sb, KERN_ERR,
+			 "Filesystem without casefold feature cannot be "
+			 "mounted with siphash");
+		return 0;
+	}
 
 	if (readonly)
 		return 1;
-- 
2.43.0