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author | Ingo Molnar <mingo@kernel.org> | 2015-03-31 10:45:47 +0200 |
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committer | Ingo Molnar <mingo@kernel.org> | 2015-03-31 10:45:47 +0200 |
commit | 36cbf25dc79cc33d623889cafba2c672b161c1ad (patch) | |
tree | 6a48140e49a19ee33d35b8e1d8bf13253aa92442 /drivers/firmware | |
parent | MAINTAINERS: Change the x86 microcode loader maintainer (diff) | |
parent | firmware: dmi_scan: Prevent dmi_num integer overflow (diff) | |
download | linux-36cbf25dc79cc33d623889cafba2c672b161c1ad.tar.xz linux-36cbf25dc79cc33d623889cafba2c672b161c1ad.zip |
Merge tag 'efi-urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into x86/urgent
Pull EFI fix from Matt Fleming:
- Fix integer overflow issue in the DMI SMBIOS 3.0 code when
calculating the number of DMI table entries. (Jean Delvare)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'drivers/firmware')
-rw-r--r-- | drivers/firmware/dmi_scan.c | 22 |
1 files changed, 7 insertions, 15 deletions
diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c index 69fac068669f..2eebd28b4c40 100644 --- a/drivers/firmware/dmi_scan.c +++ b/drivers/firmware/dmi_scan.c @@ -86,10 +86,13 @@ static void dmi_table(u8 *buf, u32 len, int num, int i = 0; /* - * Stop when we see all the items the table claimed to have - * OR we run off the end of the table (also happens) + * Stop when we have seen all the items the table claimed to have + * (SMBIOS < 3.0 only) OR we reach an end-of-table marker OR we run + * off the end of the table (should never happen but sometimes does + * on bogus implementations.) */ - while ((i < num) && (data - buf + sizeof(struct dmi_header)) <= len) { + while ((!num || i < num) && + (data - buf + sizeof(struct dmi_header)) <= len) { const struct dmi_header *dm = (const struct dmi_header *)data; /* @@ -529,21 +532,10 @@ static int __init dmi_smbios3_present(const u8 *buf) if (memcmp(buf, "_SM3_", 5) == 0 && buf[6] < 32 && dmi_checksum(buf, buf[6])) { dmi_ver = get_unaligned_be16(buf + 7); + dmi_num = 0; /* No longer specified */ dmi_len = get_unaligned_le32(buf + 12); dmi_base = get_unaligned_le64(buf + 16); - /* - * The 64-bit SMBIOS 3.0 entry point no longer has a field - * containing the number of structures present in the table. - * Instead, it defines the table size as a maximum size, and - * relies on the end-of-table structure type (#127) to be used - * to signal the end of the table. - * So let's define dmi_num as an upper bound as well: each - * structure has a 4 byte header, so dmi_len / 4 is an upper - * bound for the number of structures in the table. - */ - dmi_num = dmi_len / 4; - if (dmi_walk_early(dmi_decode) == 0) { pr_info("SMBIOS %d.%d present.\n", dmi_ver >> 8, dmi_ver & 0xFF); |