--- /dev/null
+From 458c15dfbce62c35fefd9ca637b20a051309c9f1 Mon Sep 17 00:00:00 2001
+From: Chao Yu <chao@kernel.org>
+Date: Tue, 23 May 2023 11:58:22 +0800
+Subject: f2fs: don't reset unchangable mount option in f2fs_remount()
+
+From: Chao Yu <chao@kernel.org>
+
+commit 458c15dfbce62c35fefd9ca637b20a051309c9f1 upstream.
+
+syzbot reports a bug as below:
+
+general protection fault, probably for non-canonical address 0xdffffc0000000009: 0000 [#1] PREEMPT SMP KASAN
+RIP: 0010:__lock_acquire+0x69/0x2000 kernel/locking/lockdep.c:4942
+Call Trace:
+ lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5691
+ __raw_write_lock include/linux/rwlock_api_smp.h:209 [inline]
+ _raw_write_lock+0x2e/0x40 kernel/locking/spinlock.c:300
+ __drop_extent_tree+0x3ac/0x660 fs/f2fs/extent_cache.c:1100
+ f2fs_drop_extent_tree+0x17/0x30 fs/f2fs/extent_cache.c:1116
+ f2fs_insert_range+0x2d5/0x3c0 fs/f2fs/file.c:1664
+ f2fs_fallocate+0x4e4/0x6d0 fs/f2fs/file.c:1838
+ vfs_fallocate+0x54b/0x6b0 fs/open.c:324
+ ksys_fallocate fs/open.c:347 [inline]
+ __do_sys_fallocate fs/open.c:355 [inline]
+ __se_sys_fallocate fs/open.c:353 [inline]
+ __x64_sys_fallocate+0xbd/0x100 fs/open.c:353
+ do_syscall_x64 arch/x86/entry/common.c:50 [inline]
+ do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
+ entry_SYSCALL_64_after_hwframe+0x63/0xcd
+
+The root cause is race condition as below:
+- since it tries to remount rw filesystem, so that do_remount won't
+call sb_prepare_remount_readonly to block fallocate, there may be race
+condition in between remount and fallocate.
+- in f2fs_remount(), default_options() will reset mount option to default
+one, and then update it based on result of parse_options(), so there is
+a hole which race condition can happen.
+
+Thread A Thread B
+- f2fs_fill_super
+ - parse_options
+ - clear_opt(READ_EXTENT_CACHE)
+
+- f2fs_remount
+ - default_options
+ - set_opt(READ_EXTENT_CACHE)
+ - f2fs_fallocate
+ - f2fs_insert_range
+ - f2fs_drop_extent_tree
+ - __drop_extent_tree
+ - __may_extent_tree
+ - test_opt(READ_EXTENT_CACHE) return true
+ - write_lock(&et->lock) access NULL pointer
+ - parse_options
+ - clear_opt(READ_EXTENT_CACHE)
+
+Cc: <stable@vger.kernel.org>
+Reported-by: syzbot+d015b6c2fbb5c383bf08@syzkaller.appspotmail.com
+Closes: https://lore.kernel.org/linux-f2fs-devel/20230522124203.3838360-1-chao@kernel.org
+Signed-off-by: Chao Yu <chao@kernel.org>
+Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ fs/f2fs/super.c | 30 ++++++++++++++++++------------
+ 1 file changed, 18 insertions(+), 12 deletions(-)
+
+--- a/fs/f2fs/super.c
++++ b/fs/f2fs/super.c
+@@ -2086,9 +2086,22 @@ static int f2fs_show_options(struct seq_
+ return 0;
+ }
+
+-static void default_options(struct f2fs_sb_info *sbi)
++static void default_options(struct f2fs_sb_info *sbi, bool remount)
+ {
+ /* init some FS parameters */
++ if (!remount) {
++ set_opt(sbi, READ_EXTENT_CACHE);
++ clear_opt(sbi, DISABLE_CHECKPOINT);
++
++ if (f2fs_hw_support_discard(sbi) || f2fs_hw_should_discard(sbi))
++ set_opt(sbi, DISCARD);
++
++ if (f2fs_sb_has_blkzoned(sbi))
++ F2FS_OPTION(sbi).discard_unit = DISCARD_UNIT_SECTION;
++ else
++ F2FS_OPTION(sbi).discard_unit = DISCARD_UNIT_BLOCK;
++ }
++
+ if (f2fs_sb_has_readonly(sbi))
+ F2FS_OPTION(sbi).active_logs = NR_CURSEG_RO_TYPE;
+ else
+@@ -2118,23 +2131,16 @@ static void default_options(struct f2fs_
+ set_opt(sbi, INLINE_XATTR);
+ set_opt(sbi, INLINE_DATA);
+ set_opt(sbi, INLINE_DENTRY);
+- set_opt(sbi, READ_EXTENT_CACHE);
+ set_opt(sbi, NOHEAP);
+- clear_opt(sbi, DISABLE_CHECKPOINT);
+ set_opt(sbi, MERGE_CHECKPOINT);
+ F2FS_OPTION(sbi).unusable_cap = 0;
+ sbi->sb->s_flags |= SB_LAZYTIME;
+ if (!f2fs_is_readonly(sbi))
+ set_opt(sbi, FLUSH_MERGE);
+- if (f2fs_hw_support_discard(sbi) || f2fs_hw_should_discard(sbi))
+- set_opt(sbi, DISCARD);
+- if (f2fs_sb_has_blkzoned(sbi)) {
++ if (f2fs_sb_has_blkzoned(sbi))
+ F2FS_OPTION(sbi).fs_mode = FS_MODE_LFS;
+- F2FS_OPTION(sbi).discard_unit = DISCARD_UNIT_SECTION;
+- } else {
++ else
+ F2FS_OPTION(sbi).fs_mode = FS_MODE_ADAPTIVE;
+- F2FS_OPTION(sbi).discard_unit = DISCARD_UNIT_BLOCK;
+- }
+
+ #ifdef CONFIG_F2FS_FS_XATTR
+ set_opt(sbi, XATTR_USER);
+@@ -2306,7 +2312,7 @@ static int f2fs_remount(struct super_blo
+ clear_sbi_flag(sbi, SBI_NEED_SB_WRITE);
+ }
+
+- default_options(sbi);
++ default_options(sbi, true);
+
+ /* parse mount options */
+ err = parse_options(sb, data, true);
+@@ -4357,7 +4363,7 @@ try_onemore:
+ sbi->s_chksum_seed = f2fs_chksum(sbi, ~0, raw_super->uuid,
+ sizeof(raw_super->uuid));
+
+- default_options(sbi);
++ default_options(sbi, false);
+ /* parse mount options */
+ options = kstrdup((const char *)data, GFP_KERNEL);
+ if (data && !options) {
--- /dev/null
+From 5eda1ad1aaffdfebdecf7a164e586060a210f74f Mon Sep 17 00:00:00 2001
+From: Jaegeuk Kim <jaegeuk@kernel.org>
+Date: Wed, 28 Jun 2023 01:00:56 -0700
+Subject: f2fs: fix deadlock in i_xattr_sem and inode page lock
+
+From: Jaegeuk Kim <jaegeuk@kernel.org>
+
+commit 5eda1ad1aaffdfebdecf7a164e586060a210f74f upstream.
+
+Thread #1:
+
+[122554.641906][ T92] f2fs_getxattr+0xd4/0x5fc
+ -> waiting for f2fs_down_read(&F2FS_I(inode)->i_xattr_sem);
+
+[122554.641927][ T92] __f2fs_get_acl+0x50/0x284
+[122554.641948][ T92] f2fs_init_acl+0x84/0x54c
+[122554.641969][ T92] f2fs_init_inode_metadata+0x460/0x5f0
+[122554.641990][ T92] f2fs_add_inline_entry+0x11c/0x350
+ -> Locked dir->inode_page by f2fs_get_node_page()
+
+[122554.642009][ T92] f2fs_do_add_link+0x100/0x1e4
+[122554.642025][ T92] f2fs_create+0xf4/0x22c
+[122554.642047][ T92] vfs_create+0x130/0x1f4
+
+Thread #2:
+
+[123996.386358][ T92] __get_node_page+0x8c/0x504
+ -> waiting for dir->inode_page lock
+
+[123996.386383][ T92] read_all_xattrs+0x11c/0x1f4
+[123996.386405][ T92] __f2fs_setxattr+0xcc/0x528
+[123996.386424][ T92] f2fs_setxattr+0x158/0x1f4
+ -> f2fs_down_write(&F2FS_I(inode)->i_xattr_sem);
+
+[123996.386443][ T92] __f2fs_set_acl+0x328/0x430
+[123996.386618][ T92] f2fs_set_acl+0x38/0x50
+[123996.386642][ T92] posix_acl_chmod+0xc8/0x1c8
+[123996.386669][ T92] f2fs_setattr+0x5e0/0x6bc
+[123996.386689][ T92] notify_change+0x4d8/0x580
+[123996.386717][ T92] chmod_common+0xd8/0x184
+[123996.386748][ T92] do_fchmodat+0x60/0x124
+[123996.386766][ T92] __arm64_sys_fchmodat+0x28/0x3c
+
+Cc: <stable@vger.kernel.org>
+Fixes: 27161f13e3c3 "f2fs: avoid race in between read xattr & write xattr"
+Reviewed-by: Chao Yu <chao@kernel.org>
+Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ fs/f2fs/dir.c | 9 ++++++++-
+ fs/f2fs/xattr.c | 6 ++++--
+ 2 files changed, 12 insertions(+), 3 deletions(-)
+
+--- a/fs/f2fs/dir.c
++++ b/fs/f2fs/dir.c
+@@ -775,8 +775,15 @@ int f2fs_add_dentry(struct inode *dir, c
+ {
+ int err = -EAGAIN;
+
+- if (f2fs_has_inline_dentry(dir))
++ if (f2fs_has_inline_dentry(dir)) {
++ /*
++ * Should get i_xattr_sem to keep the lock order:
++ * i_xattr_sem -> inode_page lock used by f2fs_setxattr.
++ */
++ f2fs_down_read(&F2FS_I(dir)->i_xattr_sem);
+ err = f2fs_add_inline_entry(dir, fname, inode, ino, mode);
++ f2fs_up_read(&F2FS_I(dir)->i_xattr_sem);
++ }
+ if (err == -EAGAIN)
+ err = f2fs_add_regular_entry(dir, fname, inode, ino, mode);
+
+--- a/fs/f2fs/xattr.c
++++ b/fs/f2fs/xattr.c
+@@ -528,10 +528,12 @@ int f2fs_getxattr(struct inode *inode, i
+ if (len > F2FS_NAME_LEN)
+ return -ERANGE;
+
+- f2fs_down_read(&F2FS_I(inode)->i_xattr_sem);
++ if (!ipage)
++ f2fs_down_read(&F2FS_I(inode)->i_xattr_sem);
+ error = lookup_all_xattrs(inode, ipage, index, len, name,
+ &entry, &base_addr, &base_size, &is_inline);
+- f2fs_up_read(&F2FS_I(inode)->i_xattr_sem);
++ if (!ipage)
++ f2fs_up_read(&F2FS_I(inode)->i_xattr_sem);
+ if (error)
+ return error;
+
projects / thirdparty / kernel / stable-queue.git / commitdiff
