[PATCH AUTOSEL 6.7 15/58] fs/ntfs3: Add NULL ptr dereference checking at the end of attr_allocate_frame()

From: Sasha Levin
Date: Mon Feb 12 2024 - 19:22:29 EST


From: Konstantin Komarov <almaz.alexandrovich@xxxxxxxxxxxxxxxxxxxx>

[ Upstream commit aaab47f204aaf47838241d57bf8662c8840de60a ]

It is preferable to exit through the out: label because
internal debugging functions are located there.

Signed-off-by: Konstantin Komarov <almaz.alexandrovich@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/ntfs3/attrib.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/fs/ntfs3/attrib.c b/fs/ntfs3/attrib.c
index 4b78b669a3bd..646e2dad1b75 100644
--- a/fs/ntfs3/attrib.c
+++ b/fs/ntfs3/attrib.c
@@ -1743,8 +1743,10 @@ int attr_allocate_frame(struct ntfs_inode *ni, CLST frame, size_t compr_size,
le_b = NULL;
attr_b = ni_find_attr(ni, NULL, &le_b, ATTR_DATA, NULL,
0, NULL, &mi_b);
- if (!attr_b)
- return -ENOENT;
+ if (!attr_b) {
+ err = -ENOENT;
+ goto out;
+ }

attr = attr_b;
le = le_b;
@@ -1825,13 +1827,15 @@ int attr_allocate_frame(struct ntfs_inode *ni, CLST frame, size_t compr_size,
ok:
run_truncate_around(run, vcn);
out:
- if (new_valid > data_size)
- new_valid = data_size;
+ if (attr_b) {
+ if (new_valid > data_size)
+ new_valid = data_size;

- valid_size = le64_to_cpu(attr_b->nres.valid_size);
- if (new_valid != valid_size) {
- attr_b->nres.valid_size = cpu_to_le64(valid_size);
- mi_b->dirty = true;
+ valid_size = le64_to_cpu(attr_b->nres.valid_size);
+ if (new_valid != valid_size) {
+ attr_b->nres.valid_size = cpu_to_le64(valid_size);
+ mi_b->dirty = true;
+ }
}

return err;
--
2.43.0