git: 7bc852d94dbf - stable/14 - pci: propagate vpd read error

From: John Baldwin <jhb_at_FreeBSD.org>
Date: Tue, 29 Apr 2025 18:30:30 UTC
The branch stable/14 has been updated by jhb:

URL: https://cgit.FreeBSD.org/src/commit/?id=7bc852d94dbf01d4feacd4f2a23b1ac22aea694c

commit 7bc852d94dbf01d4feacd4f2a23b1ac22aea694c
Author:     Ryan Libby <rlibby@FreeBSD.org>
AuthorDate: 2024-07-07 23:46:58 +0000
Commit:     John Baldwin <jhb@FreeBSD.org>
CommitDate: 2025-04-29 14:17:01 +0000

    pci: propagate vpd read error
    
    On read error, we would return -1, but not handle it, causing a zero
    size malloc of value, and then we wouldd unconditionally write
    value[-1 + 1] = '\0'.  This should be harmless in terms of buffer
    overflow because we should get a minimum non-zero size allocation from
    malloc, but it also effectively swallowed the error.
    
    Reported by:    GCC -Wstringop-overflow
    Reviewed by:    kib, se
    Differential Revision:  https://reviews.freebsd.org/D45895
    
    (cherry picked from commit 39bda097c03780e26e6a25ff59a3e8e77c77563f)
---
 sys/dev/pci/pci.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/sys/dev/pci/pci.c b/sys/dev/pci/pci.c
index dde50afd9319..8224a6829f3e 100644
--- a/sys/dev/pci/pci.c
+++ b/sys/dev/pci/pci.c
@@ -1196,7 +1196,7 @@ vpd_read_elem_data(struct vpd_readstate *vrs, char keyword[2], char **value, int
 	int len;
 
 	len = vpd_read_elem_head(vrs, keyword);
-	if (len > maxlen)
+	if (len < 0 || len > maxlen)
 		return (-1);
 	*value = vpd_read_value(vrs, len);
 
@@ -1217,7 +1217,7 @@ vpd_fixup_cksum(struct vpd_readstate *vrs, char *rvstring, int len)
 }
 
 /* fetch one read-only element and return size of heading + data */
-static size_t
+static int
 next_vpd_ro_elem(struct vpd_readstate *vrs, int maxsize)
 {
 	struct pcicfg_vpd *vpd;
@@ -1251,7 +1251,7 @@ next_vpd_ro_elem(struct vpd_readstate *vrs, int maxsize)
 }
 
 /* fetch one writable element and return size of heading + data */
-static size_t
+static int
 next_vpd_rw_elem(struct vpd_readstate *vrs, int maxsize)
 {
 	struct pcicfg_vpd *vpd;