6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Yemu Lu <redacted>
commit 64d9183203eebe33de6188b70a8c1e91f52885db upstream.
fat_ent_write() may have committed the new link to the primary FAT but
then failed on the mirror copy, leaving the chain pointing to new_dclus
even though the caller will free it. Restore the original value to keep
the chain consistent.
Link: https://lore.kernel.org/20260525085649.781643-1-n05ec@lzu.edu.cn (local)
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Yemu Lu <redacted>
Signed-off-by: Ren Wei <redacted>
Reported-by: Yuan Tan <redacted>
Reported-by: Yifan Wu <redacted>
Reported-by: Juefei Pu <redacted>
Reported-by: Xin Liu <redacted>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Christian Brauner <brauner@kernel.org>
Cc: <redacted>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/fat/misc.c | 4 ++++
1 file changed, 4 insertions(+)
--- a/fs/fat/misc.c
+++ b/fs/fat/misc.c
@@ -133,7 +133,11 @@ int fat_chain_add(struct inode *inode, i
ret = fat_ent_read(inode, &fatent, last);
if (ret >= 0) {
int wait = inode_needs_sync(inode);
+ int old = ret;
+
ret = fat_ent_write(inode, &fatent, new_dclus, wait);
+ if (ret < 0)
+ fat_ent_write(inode, &fatent, old, wait);
fatent_brelse(&fatent);
}
if (ret < 0)