ACPI / APEI: Make GHES estatus header validation more user friendly

ghes_read_estatus() checks various lengths in the top-level header to
ensure the CPER records to be read aren't obviously corrupt.

Take the opportunity to make this more user-friendly, printing a
(ratelimited) message about the nature of the header format error.

Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: James Morse <james.morse@arm.com>
[ rjw: Add missing 'static' ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
James Morse 2019-01-29 18:48:54 +00:00 committed by Rafael J. Wysocki
parent f2a7e059aa
commit f2a681b916

View file

@ -293,6 +293,30 @@ static void ghes_copy_tofrom_phys(void *buffer, u64 paddr, u32 len,
}
}
/* Check the top-level record header has an appropriate size. */
static int __ghes_check_estatus(struct ghes *ghes,
struct acpi_hest_generic_status *estatus)
{
u32 len = cper_estatus_len(estatus);
if (len < sizeof(*estatus)) {
pr_warn_ratelimited(FW_WARN GHES_PFX "Truncated error status block!\n");
return -EIO;
}
if (len > ghes->generic->error_block_length) {
pr_warn_ratelimited(FW_WARN GHES_PFX "Invalid error status block length!\n");
return -EIO;
}
if (cper_estatus_check_header(estatus)) {
pr_warn_ratelimited(FW_WARN GHES_PFX "Invalid CPER header!\n");
return -EIO;
}
return 0;
}
static int ghes_read_estatus(struct ghes *ghes,
struct acpi_hest_generic_status *estatus,
u64 *buf_paddr, enum fixed_addresses fixmap_idx)
@ -319,27 +343,21 @@ static int ghes_read_estatus(struct ghes *ghes,
return -ENOENT;
}
rc = -EIO;
rc = __ghes_check_estatus(ghes, estatus);
if (rc)
return rc;
len = cper_estatus_len(estatus);
if (len < sizeof(*estatus))
goto err_read_block;
if (len > ghes->generic->error_block_length)
goto err_read_block;
if (cper_estatus_check_header(estatus))
goto err_read_block;
ghes_copy_tofrom_phys(estatus + 1,
*buf_paddr + sizeof(*estatus),
len - sizeof(*estatus), 1, fixmap_idx);
if (cper_estatus_check(estatus))
goto err_read_block;
rc = 0;
err_read_block:
if (rc)
if (cper_estatus_check(estatus)) {
pr_warn_ratelimited(FW_WARN GHES_PFX
"Failed to read error status block!\n");
return -EIO;
}
return rc;
return 0;
}
static void ghes_clear_estatus(struct ghes *ghes,