[SRU][J/N/Q/R:Unstable][PATCH 1/1] UBUNTU: SAUCE: efi: Fix swapped arguments to bsearch() in efi_status_to_*()

[Dongdong Tao]

BugLink: https://bugs.launchpad.net/bugs/2141276

The bsearch() function signature is:
  void *bsearch(const void *key, const void *base,
                size_t nmemb, size_t size,
                int (*compar)(const void *, const void *));

The third argument is the number of elements (nmemb), and the fourth
is the size of each element. However, in efi_status_to_err() and
efi_status_to_str(), these arguments were passed in the wrong order:
sizeof(struct efi_error_code) was passed as nmemb, and num (the actual
count) was passed as size.

This bug causes bsearch to calculate incorrect element offsets, reading
at every 12 bytes instead of every 24 bytes (on 64-bit), potentially
returning incorrect results or failing to find valid status codes.

The bug was introduced in the SAUCE patch:
  "UBUNTU: SAUCE: (lockdown) Add efi_status_to_str() and rework
   efi_status_to_err()."

which was cherry-picked from kernel-ark commit 2ae9082db0b5.

(backported from commit 49bcc48074ba1f9c772b5c7ae11123a8ed3e0ac1
 https://gitlab.com/cki-project/kernel-ark)

Signed-off-by: Dongdong Tao <dongdong.tao at canonical.com>
---
 drivers/firmware/efi/efi.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 715b736be77a..3f0451709fbf 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -930,7 +930,7 @@ int efi_status_to_err(efi_status_t status)
 	size_t num = sizeof(efi_error_codes) / sizeof(struct efi_error_code);
 
 	found = bsearch((void *)(uintptr_t)status, efi_error_codes,
-			sizeof(struct efi_error_code), num,
+			num, sizeof(struct efi_error_code),
 			efi_status_cmp_bsearch);
 	if (!found)
 		return -EINVAL;
@@ -944,7 +944,7 @@ efi_status_to_str(efi_status_t status)
 	size_t num = sizeof(efi_error_codes) / sizeof(struct efi_error_code);
 
 	found = bsearch((void *)(uintptr_t)status, efi_error_codes,
-			sizeof(struct efi_error_code), num,
+			num, sizeof(struct efi_error_code),
 			efi_status_cmp_bsearch);
 	if (!found)
 		return "Unknown error code";
-- 
2.39.5 (Apple Git-154)