From 080da7b2fc28abdad5cdacf569a1ce83c6c27752 Mon Sep 17 00:00:00 2001 From: Wang Zhaolong Date: Fri, 16 May 2025 17:12:56 +0800 Subject: [PATCH] smb: client: Reset all search buffer pointers when releasing buffer commit e48f9d849bfdec276eebf782a84fd4dfbe1c14c0 upstream. Multiple pointers in struct cifs_search_info (ntwrk_buf_start, srch_entries_start, and last_entry) point to the same allocated buffer. However, when freeing this buffer, only ntwrk_buf_start was set to NULL, while the other pointers remained pointing to freed memory. This is defensive programming to prevent potential issues with stale pointers. While the active UAF vulnerability is fixed by the previous patch, this change ensures consistent pointer state and more robust error handling. Signed-off-by: Wang Zhaolong Cc: stable@vger.kernel.org Reviewed-by: Paulo Alcantara (Red Hat) Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- fs/smb/client/readdir.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/smb/client/readdir.c b/fs/smb/client/readdir.c index 338e4cd81fbd5..402ac06ae9b6f 100644 --- a/fs/smb/client/readdir.c +++ b/fs/smb/client/readdir.c @@ -765,7 +765,10 @@ find_cifs_entry(const unsigned int xid, struct cifs_tcon *tcon, loff_t pos, else cifs_buf_release(cfile->srch_inf. ntwrk_buf_start); + /* Reset all pointers to the network buffer to prevent stale references */ cfile->srch_inf.ntwrk_buf_start = NULL; + cfile->srch_inf.srch_entries_start = NULL; + cfile->srch_inf.last_entry = NULL; } rc = initiate_cifs_search(xid, file, full_path); if (rc) { -- 2.47.3