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authorJia-Ju Bai <baijiaju@buaa.edu.cn>2023-03-21 16:22:11 +0300
committerKonstantin Komarov <almaz.alexandrovich@paragon-software.com>2023-07-02 23:21:23 +0300
commit97498cd610c0d030a7bd49a7efad974790661162 (patch)
tree2dcbb6f015fccd76a495707baec7c3eefc78fd85 /fs/ntfs3/record.c
parentc9db0ff04649aa0b45f497183c957fe260f229f6 (diff)
downloadlinux-97498cd610c0d030a7bd49a7efad974790661162.tar.xz
fs: ntfs3: Fix possible null-pointer dereferences in mi_read()
In a previous commit 2681631c2973 ("fs/ntfs3: Add null pointer check to attr_load_runs_vcn"), ni can be NULL in attr_load_runs_vcn(), and thus it should be checked before being used. However, in the call stack of this commit, mft_ni in mi_read() is aliased with ni in attr_load_runs_vcn(), and it is also used in mi_read() at two places: mi_read() rw_lock = &mft_ni->file.run_lock -> No check attr_load_runs_vcn(mft_ni, ...) ni (namely mft_ni) is checked in the previous commit attr_load_runs_vcn(..., &mft_ni->file.run) -> No check Thus, to avoid possible null-pointer dereferences, the related checks should be added. These bugs are reported by a static analysis tool implemented by myself, and they are found by extending a known bug fixed in the previous commit. Thus, they could be theoretical bugs. Signed-off-by: Jia-Ju Bai <baijiaju@buaa.edu.cn> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Diffstat (limited to 'fs/ntfs3/record.c')
-rw-r--r--fs/ntfs3/record.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/ntfs3/record.c b/fs/ntfs3/record.c
index 2a281cead2bc..7060f784c2d7 100644
--- a/fs/ntfs3/record.c
+++ b/fs/ntfs3/record.c
@@ -124,7 +124,7 @@ int mi_read(struct mft_inode *mi, bool is_mft)
struct rw_semaphore *rw_lock = NULL;
if (is_mounted(sbi)) {
- if (!is_mft) {
+ if (!is_mft && mft_ni) {
rw_lock = &mft_ni->file.run_lock;
down_read(rw_lock);
}
@@ -148,7 +148,7 @@ int mi_read(struct mft_inode *mi, bool is_mft)
ni_lock(mft_ni);
down_write(rw_lock);
}
- err = attr_load_runs_vcn(mft_ni, ATTR_DATA, NULL, 0, &mft_ni->file.run,
+ err = attr_load_runs_vcn(mft_ni, ATTR_DATA, NULL, 0, run,
vbo >> sbi->cluster_bits);
if (rw_lock) {
up_write(rw_lock);