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authorJames Morse <james.morse@arm.com>2019-01-29 21:48:54 +0300
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2019-02-08 01:10:45 +0300
commitf2a681b9160b9c80826b3062e71371cfc82b4863 (patch)
tree11986398f2f42320e28409e2dc63bf665f2241ef /drivers/acpi
parentf2a7e059aa7a6a22a6f4612f31ee29e726a3bfd0 (diff)
downloadlinux-f2a681b9160b9c80826b3062e71371cfc82b4863.tar.xz
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>
Diffstat (limited to 'drivers/acpi')
-rw-r--r--drivers/acpi/apei/ghes.c46
1 files changed, 32 insertions, 14 deletions
diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 54746a791f3f..4fb274bb209e 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -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,