git: b87ad4f2db6d - stable/12 - stand/efihttp: Work around a bug in edk2 http instance reconfiguration

From: Kyle Evans <kevans_at_FreeBSD.org>
Date: Fri, 08 Oct 2021 01:16:46 UTC
The branch stable/12 has been updated by kevans:

URL: https://cgit.FreeBSD.org/src/commit/?id=b87ad4f2db6dfc3b66464a689c399f666fa64d39

commit b87ad4f2db6dfc3b66464a689c399f666fa64d39
Author:     D Scott Phillips <scottph@FreeBSD.org>
AuthorDate: 2020-09-09 16:35:51 +0000
Commit:     Kyle Evans <kevans@FreeBSD.org>
CommitDate: 2021-10-08 01:15:59 +0000

    stand/efihttp: Work around a bug in edk2 http instance reconfiguration
    
    A bug in the EFI HTTP driver of TianoCore EDK2 causes memory
    corruption when an http instance that uses tls is reconfigured,
    leading to a crash.
    
    Work around this by forcing a new http instance for each request
    instead of reconfiguring the existing one.
    
    The upstream bug report is https://bugzilla.tianocore.org/show_bug.cgi?id=1917
    
    (cherry picked from commit d455cd5ac36f4c1ac76f04e2c2bb4bfb00fe8bcd)
---
 stand/efi/libefi/efihttp.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/stand/efi/libefi/efihttp.c b/stand/efi/libefi/efihttp.c
index 074c85dcdef0..05d338fbaf04 100644
--- a/stand/efi/libefi/efihttp.c
+++ b/stand/efi/libefi/efihttp.c
@@ -576,6 +576,14 @@ efihttp_fs_open(const char *path, struct open_file *f)
 	 */
 	err = _efihttp_fs_open(path, f);
 	if (err != 0) {
+		/*
+		 * Work around a bug in the EFI HTTP implementation which
+		 * causes a crash if the http instance isn't torn down
+		 * between requests.
+		 * See https://bugzilla.tianocore.org/show_bug.cgi?id=1917
+		 */
+		efihttp_dev_close(f);
+		efihttp_dev_open(f);
 		path_slash = malloc(strlen(path) + 2);
 		if (path_slash == NULL)
 			return (ENOMEM);
@@ -719,6 +727,14 @@ efihttp_fs_seek(struct open_file *f, off_t offset, int where)
 		path = fh->path;
 		fh->path = NULL;
 		efihttp_fs_close(f);
+		/*
+		 * Work around a bug in the EFI HTTP implementation which
+		 * causes a crash if the http instance isn't torn down
+		 * between requests.
+		 * See https://bugzilla.tianocore.org/show_bug.cgi?id=1917
+		 */
+		efihttp_dev_close(f);
+		efihttp_dev_open(f);
 		err = efihttp_fs_open(path, f);
 		free(path);
 		if (err != 0)