smb: client: compress: fix bad encoding on last LZ77 flag

ematsumiya · smfrench · commit a13e942a03fe · 2026-04-19T09:46:46.000-05:00
End-of-stream flag could lead to UB because of int promotion
(overwriting signed bit).

Fix it by changing operand from '1' to '1UL'.

Signed-off-by: Enzo Matsumiya &lt;ematsumiya@suse.de&gt;
Signed-off-by: Steve French &lt;stfrench@microsoft.com&gt;
diff --git a/fs/smb/client/compress/lz77.c b/fs/smb/client/compress/lz77.c
@@ -221,7 +221,7 @@ noinline int lz77_compress(const void *src, u32 slen, void *dst, u32 *dlen)
 	}
 
 	flag <<= (32 - flag_count);
-	flag |= (1 << (32 - flag_count)) - 1;
+	flag |= (1UL << (32 - flag_count)) - 1;
 	lz77_write32(flag_pos, flag);
 
 	*dlen = dstp - dst;

Original file line number	Diff line number	Diff line change
`@@ -221,7 +221,7 @@ noinline int lz77_compress(const void src, u32 slen, void dst, u32 *dlen)`
`221`	`221`	`}`
`222`	`222`
`223`	`223`	`flag <<= (32 - flag_count);`
`224`		`- flag \|= (1 << (32 - flag_count)) - 1;`
	`224`	`+ flag \|= (1UL << (32 - flag_count)) - 1;`
`225`	`225`	`lz77_write32(flag_pos, flag);`
`226`	`226`
`227`	`227`	`*dlen = dstp - dst;`