5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Namjae Jeon <linkinjeon@xxxxxxxxxx>
[ Upstream commit 9da33619e0ca53627641bc97d1b93ec741299111 ]
bitmap clear loop will take long time in __exfat_free_cluster()
if data size of file/dir enty is invalid.
If cluster bit in bitmap is already clear, stop clearing bitmap go to
out of loop.
Fixes: 31023864e67a ("exfat: add fat entry operations")
Reported-by: Kun Hu <huk23@xxxxxxxxxxxxxx>, Jiaji Qin <jjtan24@xxxxxxxxxxxxxx>
Reviewed-by: Sungjong Seo <sj1557.seo@xxxxxxxxxxx>
Signed-off-by: Namjae Jeon <linkinjeon@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/exfat/balloc.c | 10 ++++++++--
fs/exfat/exfat_fs.h | 2 +-
fs/exfat/fatent.c | 11 +++++++----
3 files changed, 16 insertions(+), 7 deletions(-)
diff --git a/fs/exfat/balloc.c b/fs/exfat/balloc.c
index 144617066a2bf..26808f0d3e9ff 100644
--- a/fs/exfat/balloc.c
+++ b/fs/exfat/balloc.c
@@ -160,7 +160,7 @@ int exfat_set_bitmap(struct inode *inode, unsigned int clu, bool sync)
return 0;
}
-void exfat_clear_bitmap(struct inode *inode, unsigned int clu, bool sync)
+int exfat_clear_bitmap(struct inode *inode, unsigned int clu, bool sync)
{
int i, b;
unsigned int ent_idx;
@@ -169,13 +169,17 @@ void exfat_clear_bitmap(struct inode *inode, unsigned int clu, bool sync)
struct exfat_mount_options *opts = &sbi->options;
if (!is_valid_cluster(sbi, clu))
- return;
+ return -EIO;
ent_idx = CLUSTER_TO_BITMAP_ENT(clu);
i = BITMAP_OFFSET_SECTOR_INDEX(sb, ent_idx);
b = BITMAP_OFFSET_BIT_IN_SECTOR(sb, ent_idx);
+ if (!test_bit_le(b, sbi->vol_amap[i]->b_data))
+ return -EIO;
+
clear_bit_le(b, sbi->vol_amap[i]->b_data);
+
exfat_update_bh(sbi->vol_amap[i], sync);
if (opts->discard) {
@@ -190,6 +194,8 @@ void exfat_clear_bitmap(struct inode *inode, unsigned int clu, bool sync)
opts->discard = 0;
}
}
+
+ return 0;
}
/*
diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h
index 58816ee3162c4..e242d7758f782 100644
--- a/fs/exfat/exfat_fs.h
+++ b/fs/exfat/exfat_fs.h
@@ -420,7 +420,7 @@ int exfat_count_num_clusters(struct super_block *sb,
int exfat_load_bitmap(struct super_block *sb);
void exfat_free_bitmap(struct exfat_sb_info *sbi);
int exfat_set_bitmap(struct inode *inode, unsigned int clu, bool sync);
-void exfat_clear_bitmap(struct inode *inode, unsigned int clu, bool sync);
+int exfat_clear_bitmap(struct inode *inode, unsigned int clu, bool sync);
unsigned int exfat_find_free_bitmap(struct super_block *sb, unsigned int clu);
int exfat_count_used_clusters(struct super_block *sb, unsigned int *ret_count);
int exfat_trim_fs(struct inode *inode, struct fstrim_range *range);
diff --git a/fs/exfat/fatent.c b/fs/exfat/fatent.c
index 8f07504e53458..9c116a58544da 100644
--- a/fs/exfat/fatent.c
+++ b/fs/exfat/fatent.c
@@ -174,6 +174,7 @@ static int __exfat_free_cluster(struct inode *inode, struct exfat_chain *p_chain
BITMAP_OFFSET_SECTOR_INDEX(sb, CLUSTER_TO_BITMAP_ENT(clu));
if (p_chain->flags == ALLOC_NO_FAT_CHAIN) {
+ int err;
unsigned int last_cluster = p_chain->dir + p_chain->size - 1;
do {
bool sync = false;
@@ -188,7 +189,9 @@ static int __exfat_free_cluster(struct inode *inode, struct exfat_chain *p_chain
cur_cmap_i = next_cmap_i;
}
- exfat_clear_bitmap(inode, clu, (sync && IS_DIRSYNC(inode)));
+ err = exfat_clear_bitmap(inode, clu, (sync && IS_DIRSYNC(inode)));
+ if (err)
+ break;
clu++;
num_clusters++;
} while (num_clusters < p_chain->size);
@@ -209,12 +212,13 @@ static int __exfat_free_cluster(struct inode *inode, struct exfat_chain *p_chain
cur_cmap_i = next_cmap_i;
}
- exfat_clear_bitmap(inode, clu, (sync && IS_DIRSYNC(inode)));
+ if (exfat_clear_bitmap(inode, clu, (sync && IS_DIRSYNC(inode))))
+ break;
clu = n_clu;
num_clusters++;
if (err)
- goto dec_used_clus;
+ break;
if (num_clusters >= sbi->num_clusters - EXFAT_FIRST_CLUSTER) {
/*
@@ -228,7 +232,6 @@ static int __exfat_free_cluster(struct inode *inode, struct exfat_chain *p_chain
} while (clu != EXFAT_EOF_CLUSTER);
}
-dec_used_clus:
sbi->used_clusters -= num_clusters;
return 0;
}
--
2.39.5
