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authorTakashi Iwai <tiwai@suse.de>2017-12-14 13:31:16 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-01-02 20:33:19 +0100
commitdb09203e325264e8d3b78a74205a0a250fe01b3b (patch)
tree3d687b6f413ad02e1727e6fce74b3f334802156f
parent03028e068a1f75d3b2e0989d7a452e701df0727b (diff)
ACPI: APEI / ERST: Fix missing error handling in erst_reader()
commit bb82e0b4a7e96494f0c1004ce50cec3d7b5fb3d1 upstream. The commit f6f828513290 ("pstore: pass allocated memory region back to caller") changed the check of the return value from erst_read() in erst_reader() in the following way: if (len == -ENOENT) goto skip; - else if (len < 0) { - rc = -1; + else if (len < sizeof(*rcd)) { + rc = -EIO; goto out; This introduced another bug: since the comparison with sizeof() is cast to unsigned, a negative len value doesn't hit any longer. As a result, when an error is returned from erst_read(), the code falls through, and it may eventually lead to some weird thing like memory corruption. This patch adds the negative error value check more explicitly for addressing the issue. Fixes: f6f828513290 (pstore: pass allocated memory region back to caller) Tested-by: Jerry Tang <jtang@suse.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Acked-by: Kees Cook <keescook@chromium.org> Reviewed-by: Borislav Petkov <bp@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/acpi/apei/erst.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/acpi/apei/erst.c b/drivers/acpi/apei/erst.c
index 6682c5daf742..4c9be45ea328 100644
--- a/drivers/acpi/apei/erst.c
+++ b/drivers/acpi/apei/erst.c
@@ -1020,7 +1020,7 @@ skip:
/* The record may be cleared by others, try read next record */
if (len == -ENOENT)
goto skip;
- else if (len < sizeof(*rcd)) {
+ else if (len < 0 || len < sizeof(*rcd)) {
rc = -EIO;
goto out;
}