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* [PATCH] ntfs3: Fix attr_punch_hole() null pointer derenference
@ 2022-08-15 11:07 Alon Zahavi
  2022-09-30 15:44 ` Konstantin Komarov
                   ` (2 more replies)
  0 siblings, 3 replies; 5+ messages in thread
From: Alon Zahavi @ 2022-08-15 11:07 UTC (permalink / raw)
  To: almaz.alexandrovich, ntfs3, linux-kernel; +Cc: Alon Zahavi, Tal Lossos

From: Alon Zahavi <zahavi.alon@gmail.com>

The bug occours due to a misuse of `attr` variable instead of `attr_b`.
`attr` is being initialized as NULL, then being derenfernced
as `attr->res.data_size`.

This bug causes a crash of the ntfs3 driver itself,
If compiled directly to the kernel, it crashes the whole system.

Signed-off-by: Alon Zahavi <zahavi.alon@gmail.com>
Co-developed-by: Tal Lossos <tallossos@gmail.com>
Signed-off-by: Tal Lossos <tallossos@gmail.com>
---
 fs/ntfs3/attrib.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ntfs3/attrib.c b/fs/ntfs3/attrib.c
index e8c00dda42ad..4e74bc8f01ed 100644
--- a/fs/ntfs3/attrib.c
+++ b/fs/ntfs3/attrib.c
@@ -1949,7 +1949,7 @@ int attr_punch_hole(struct ntfs_inode *ni, u64 vbo, u64 bytes, u32 *frame_size)
 		return -ENOENT;
 
 	if (!attr_b->non_res) {
-		u32 data_size = le32_to_cpu(attr->res.data_size);
+		u32 data_size = le32_to_cpu(attr_b->res.data_size);
 		u32 from, to;
 
 		if (vbo > data_size)
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2023-01-22 13:46 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-08-15 11:07 [PATCH] ntfs3: Fix attr_punch_hole() null pointer derenference Alon Zahavi
2022-09-30 15:44 ` Konstantin Komarov
2023-01-17 20:21 ` SeongJae Park
2023-01-22 13:46   ` Greg KH
2023-01-17 20:27 ` SeongJae Park

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