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| author | Theodore Ts'o <tytso@mit.edu> | 2023-05-05 22:20:29 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-05-17 14:02:06 +0200 |
| commit | 536ecbd569cb99b2e8a4422c43926590c7893aef (patch) | |
| tree | 836ab75c97f8ba6a62c1b6ec08ac27cdc7bd8959 /fs | |
| parent | 118e484989b9f1fb5e2b0c6bf57cb5b28b99add5 (diff) | |
| download | linux-stable-536ecbd569cb99b2e8a4422c43926590c7893aef.tar.gz linux-stable-536ecbd569cb99b2e8a4422c43926590c7893aef.tar.bz2 linux-stable-536ecbd569cb99b2e8a4422c43926590c7893aef.zip | |
ext4: improve error recovery code paths in __ext4_remount()
commit 4c0b4818b1f636bc96359f7817a2d8bab6370162 upstream.
If there are failures while changing the mount options in
__ext4_remount(), we need to restore the old mount options.
This commit fixes two problem. The first is there is a chance that we
will free the old quota file names before a potential failure leading
to a use-after-free. The second problem addressed in this commit is
if there is a failed read/write to read-only transition, if the quota
has already been suspended, we need to renable quota handling.
Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20230506142419.984260-2-tytso@mit.edu
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ext4/super.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 88240a163706..d6ac61f43ac3 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -6579,9 +6579,6 @@ static int __ext4_remount(struct fs_context *fc, struct super_block *sb) } #ifdef CONFIG_QUOTA - /* Release old quota file names */ - for (i = 0; i < EXT4_MAXQUOTAS; i++) - kfree(old_opts.s_qf_names[i]); if (enable_quota) { if (sb_any_quota_suspended(sb)) dquot_resume(sb, -1); @@ -6591,6 +6588,9 @@ static int __ext4_remount(struct fs_context *fc, struct super_block *sb) goto restore_opts; } } + /* Release old quota file names */ + for (i = 0; i < EXT4_MAXQUOTAS; i++) + kfree(old_opts.s_qf_names[i]); #endif if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks) ext4_release_system_zone(sb); @@ -6601,6 +6601,13 @@ static int __ext4_remount(struct fs_context *fc, struct super_block *sb) return 0; restore_opts: + /* + * If there was a failing r/w to ro transition, we may need to + * re-enable quota + */ + if ((sb->s_flags & SB_RDONLY) && !(old_sb_flags & SB_RDONLY) && + sb_any_quota_suspended(sb)) + dquot_resume(sb, -1); sb->s_flags = old_sb_flags; sbi->s_mount_opt = old_opts.s_mount_opt; sbi->s_mount_opt2 = old_opts.s_mount_opt2; |