From: Reed Riley <reed@riley.engineer>
To: "linux-bcachefs@vger.kernel.org" <linux-bcachefs@vger.kernel.org>
Subject: [PATCH] bcachefs: fix overflow in fiemap
Date: Sat, 04 May 2024 22:12:23 +0000 [thread overview]
Message-ID: <7qU8xNKAHxFIkSlLrXO1B6kyf-7DvRoJRgZloXK5qHovOzUFYbbCYhe_9Tzv1J6MgiXcakyIFiovCX3HtotUEE9fsV25jYmifgyMz_wa-Ik=@riley.engineer> (raw)
filefrag (and potentially other utilities that call fiemap) sometimes
pass ULONG_MAX as the length. fiemap_prep clamps excessively large
lengths - but the calculation of end can overflow if it occurs before
calling fiemap_prep. When this happens, filefrag assumes it has read to
the end and exits.
Signed-off-by: Reed Riley <reed@riley.engineer>
---
fs/bcachefs/fs.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/bcachefs/fs.c b/fs/bcachefs/fs.c
index 4e4442bc71e3..ff01c954bff8 100644
--- a/fs/bcachefs/fs.c
+++ b/fs/bcachefs/fs.c
@@ -996,7 +996,7 @@ static int bch2_fiemap(struct inode *vinode, struct fiemap_extent_info *info,
struct btree_iter iter;
struct bkey_s_c k;
struct bkey_buf cur, prev;
- struct bpos end = POS(ei->v.i_ino, (start + len) >> 9);
+ struct bpos end;
unsigned offset_into_extent, sectors;
bool have_extent = false;
u32 snapshot;
@@ -1006,6 +1006,7 @@ static int bch2_fiemap(struct inode *vinode, struct fiemap_extent_info *info,
if (ret)
return ret;
+ end = POS(ei->v.i_ino, (start + len) >> 9);
if (start + len < start)
return -EINVAL;
--
2.44.0
next reply other threads:[~2024-05-04 22:12 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-04 22:12 Reed Riley [this message]
2024-05-04 23:35 ` [PATCH] bcachefs: fix overflow in fiemap Kent Overstreet
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