git: 516e24e57987 - main - smbios: Harden decoding of the BCD revision

[Olivier Certner]

The branch main has been updated by olce:

URL: 
https://cgit.FreeBSD.org/src/commit/?id=516e24e57987d184cce70e7f31443653aa1a5e63

commit 516e24e57987d184cce70e7f31443653aa1a5e63
Author:     Olivier Certner <o...@freebsd.org>
AuthorDate: 2025-03-03 14:25:23 +0000
Commit:     Olivier Certner <o...@freebsd.org>
CommitDate: 2025-03-07 16:42:46 +0000

    smbios: Harden decoding of the BCD revision
    
    bcd2bin() must not be called with a value greater or equal to
    LIBKERN_LEN_BCD2BIN.
    
    MFC after:      2 weeks
    Sponsored by:   The FreeBSD Foundation
---
 sys/dev/smbios/smbios.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/sys/dev/smbios/smbios.c b/sys/dev/smbios/smbios.c
index 2cc8e3ff21c4..ca329c0f65f6 100644
--- a/sys/dev/smbios/smbios.c
+++ b/sys/dev/smbios/smbios.c
@@ -241,18 +241,20 @@ smbios_attach (device_t dev)
                            "Docrev: %u, Entry Point Revision: %u\n",
                            sc->eps3->docrev, sc->eps3->entry_point_revision);
        } else {
+               const struct smbios_eps *const eps = va;
+               const uint8_t bcd = eps->BCD_revision;
+
                sc->eps = va;
                device_printf(dev, "Entry point: v2.1 (32-bit), Version: %u.%u",
-                   sc->eps->major_version, sc->eps->minor_version);
-               if (bcd2bin(sc->eps->BCD_revision))
+                   eps->major_version, eps->minor_version);
+               if (bcd < LIBKERN_LEN_BCD2BIN && bcd2bin(bcd) != 0)
                        printf(", BCD Revision: %u.%u\n",
-                           bcd2bin(sc->eps->BCD_revision >> 4),
-                           bcd2bin(sc->eps->BCD_revision & 0x0f));
+                           bcd2bin(bcd >> 4), bcd2bin(bcd & 0x0f));
                else
                        printf("\n");
                if (bootverbose)
                        device_printf(dev, "Entry Point Revision: %u\n",
-                           sc->eps->entry_point_revision);
+                           eps->entry_point_revision);
        }
        return (0);
 }