[kbuild-all] [PATCH v3] fs/ntfs3: add a boundary check for EA_FULL

From: Edward Adam Davis <eadavis(a)sina.com&gt; the root cause is: The remaining space after the offset is less than the space needed to accommodate the next EA_FULL struct. Link: https://syzkaller.appspot.com/bug?extid=c4d950787fd5553287b7 Reported-by: syzbot+c4d950787fd5553287b7(a)syzkaller.appspotmail.com Suggested-by: Dan Carpenter <dan.carpenter(a)oracle.com&gt; Signed-off-by: Edward Adam Davis <eadavis(a)sina.com&gt; --- Changes in v3: Add Suggested-by: and fix the syntax err. fs/ntfs3/xattr.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/fs/ntfs3/xattr.c b/fs/ntfs3/xattr.c index 7de8718c68a9..c90cc453390d 100644 --- a/fs/ntfs3/xattr.c +++ b/fs/ntfs3/xattr.c @@ -52,6 +52,7 @@ static inline bool find_ea(const struct EA_FULL *ea_all, u32 bytes, for (;;) { const struct EA_FULL *ea = Add2Ptr(ea_all, *off); u32 next_off = *off + unpacked_ea_size(ea); + u32 next_len = 0; if (next_off > bytes) return false; @@ -63,6 +64,13 @@ static inline bool find_ea(const struct EA_FULL *ea_all, u32 bytes, *off = next_off; if (next_off >= bytes) return false; + + next_len = next_off + 8; + if (next_len >= bytes || + ((!ea->size) && + (next_len + ea->name_len + + le16_to_cpu(ea->elength) >= bytes))) + return false; } } -- 2.37.2