6.1-stable patches

added patches:
	efi-random-combine-bootloader-provided-rng-seed-with-rng-protocol-output.patch

diff --git a/queue-6.1/efi-random-combine-bootloader-provided-rng-seed-with-rng-protocol-output.patch b/queue-6.1/efi-random-combine-bootloader-provided-rng-seed-with-rng-protocol-output.patch
new file mode 100644 (file)
index 0000000..d123bc7
--- /dev/null
+++ b/queue-6.1/efi-random-combine-bootloader-provided-rng-seed-with-rng-protocol-output.patch
@@ -0,0 +1,180 @@
+From 196dff2712ca5a2e651977bb2fe6b05474111a83 Mon Sep 17 00:00:00 2001
+From: Ard Biesheuvel <ardb@kernel.org>
+Date: Thu, 20 Oct 2022 10:39:10 +0200
+Subject: efi: random: combine bootloader provided RNG seed with RNG protocol output
+
+From: Ard Biesheuvel <ardb@kernel.org>
+
+commit 196dff2712ca5a2e651977bb2fe6b05474111a83 upstream.
+
+Instead of blindly creating the EFI random seed configuration table if
+the RNG protocol is implemented and works, check whether such a EFI
+configuration table was provided by an earlier boot stage and if so,
+concatenate the existing and the new seeds, leaving it up to the core
+code to mix it in and credit it the way it sees fit.
+
+This can be used for, e.g., systemd-boot, to pass an additional seed to
+Linux in a way that can be consumed by the kernel very early. In that
+case, the following definitions should be used to pass the seed to the
+EFI stub:
+
+struct linux_efi_random_seed {
+      u32     size; // of the 'seed' array in bytes
+      u8      seed[];
+};
+
+The memory for the struct must be allocated as EFI_ACPI_RECLAIM_MEMORY
+pool memory, and the address of the struct in memory should be installed
+as a EFI configuration table using the following GUID:
+
+LINUX_EFI_RANDOM_SEED_TABLE_GUID        1ce1e5bc-7ceb-42f2-81e5-8aadf180f57b
+
+Note that doing so is safe even on kernels that were built without this
+patch applied, but the seed will simply be overwritten with a seed
+derived from the EFI RNG protocol, if available. The recommended seed
+size is 32 bytes, and seeds larger than 512 bytes are considered
+corrupted and ignored entirely.
+
+In order to preserve forward secrecy, seeds from previous bootloaders
+are memzero'd out, and in order to preserve memory, those older seeds
+are also freed from memory. Freeing from memory without first memzeroing
+is not safe to do, as it's possible that nothing else will ever
+overwrite those pages used by EFI.
+
+Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
+[ardb: incorporate Jason's followup changes to extend the maximum seed
+       size on the consumer end, memzero() it and drop a needless printk]
+Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/firmware/efi/efi.c             |    4 +--
+ drivers/firmware/efi/libstub/efistub.h |    2 +
+ drivers/firmware/efi/libstub/random.c  |   42 ++++++++++++++++++++++++++++-----
+ include/linux/efi.h                    |    2 -
+ 4 files changed, 40 insertions(+), 10 deletions(-)
+
+--- a/drivers/firmware/efi/efi.c
++++ b/drivers/firmware/efi/efi.c
+@@ -611,7 +611,7 @@ int __init efi_config_parse_tables(const
+ 
+               seed = early_memremap(efi_rng_seed, sizeof(*seed));
+               if (seed != NULL) {
+-                      size = min(seed->size, EFI_RANDOM_SEED_SIZE);
++                      size = min_t(u32, seed->size, SZ_1K); // sanity check
+                       early_memunmap(seed, sizeof(*seed));
+               } else {
+                       pr_err("Could not map UEFI random seed!\n");
+@@ -620,8 +620,8 @@ int __init efi_config_parse_tables(const
+                       seed = early_memremap(efi_rng_seed,
+                                             sizeof(*seed) + size);
+                       if (seed != NULL) {
+-                              pr_notice("seeding entropy pool\n");
+                               add_bootloader_randomness(seed->bits, size);
++                              memzero_explicit(seed->bits, size);
+                               early_memunmap(seed, sizeof(*seed) + size);
+                       } else {
+                               pr_err("Could not map UEFI random seed!\n");
+--- a/drivers/firmware/efi/libstub/efistub.h
++++ b/drivers/firmware/efi/libstub/efistub.h
+@@ -882,6 +882,8 @@ efi_status_t efi_get_random_bytes(unsign
+ efi_status_t efi_random_alloc(unsigned long size, unsigned long align,
+                             unsigned long *addr, unsigned long random_seed);
+ 
++efi_status_t efi_random_get_seed(void);
++
+ efi_status_t check_platform_features(void);
+ 
+ void *get_efi_config_table(efi_guid_t guid);
+--- a/drivers/firmware/efi/libstub/random.c
++++ b/drivers/firmware/efi/libstub/random.c
+@@ -67,8 +67,9 @@ efi_status_t efi_random_get_seed(void)
+       efi_guid_t rng_proto = EFI_RNG_PROTOCOL_GUID;
+       efi_guid_t rng_algo_raw = EFI_RNG_ALGORITHM_RAW;
+       efi_guid_t rng_table_guid = LINUX_EFI_RANDOM_SEED_TABLE_GUID;
++      struct linux_efi_random_seed *prev_seed, *seed = NULL;
++      int prev_seed_size = 0, seed_size = EFI_RANDOM_SEED_SIZE;
+       efi_rng_protocol_t *rng = NULL;
+-      struct linux_efi_random_seed *seed = NULL;
+       efi_status_t status;
+ 
+       status = efi_bs_call(locate_protocol, &rng_proto, NULL, (void **)&rng);
+@@ -76,18 +77,33 @@ efi_status_t efi_random_get_seed(void)
+               return status;
+ 
+       /*
++       * Check whether a seed was provided by a prior boot stage. In that
++       * case, instead of overwriting it, let's create a new buffer that can
++       * hold both, and concatenate the existing and the new seeds.
++       * Note that we should read the seed size with caution, in case the
++       * table got corrupted in memory somehow.
++       */
++      prev_seed = get_efi_config_table(LINUX_EFI_RANDOM_SEED_TABLE_GUID);
++      if (prev_seed && prev_seed->size <= 512U) {
++              prev_seed_size = prev_seed->size;
++              seed_size += prev_seed_size;
++      }
++
++      /*
+        * Use EFI_ACPI_RECLAIM_MEMORY here so that it is guaranteed that the
+        * allocation will survive a kexec reboot (although we refresh the seed
+        * beforehand)
+        */
+       status = efi_bs_call(allocate_pool, EFI_ACPI_RECLAIM_MEMORY,
+-                           sizeof(*seed) + EFI_RANDOM_SEED_SIZE,
++                           struct_size(seed, bits, seed_size),
+                            (void **)&seed);
+-      if (status != EFI_SUCCESS)
+-              return status;
++      if (status != EFI_SUCCESS) {
++              efi_warn("Failed to allocate memory for RNG seed.\n");
++              goto err_warn;
++      }
+ 
+       status = efi_call_proto(rng, get_rng, &rng_algo_raw,
+-                               EFI_RANDOM_SEED_SIZE, seed->bits);
++                              EFI_RANDOM_SEED_SIZE, seed->bits);
+ 
+       if (status == EFI_UNSUPPORTED)
+               /*
+@@ -100,14 +116,28 @@ efi_status_t efi_random_get_seed(void)
+       if (status != EFI_SUCCESS)
+               goto err_freepool;
+ 
+-      seed->size = EFI_RANDOM_SEED_SIZE;
++      seed->size = seed_size;
++      if (prev_seed_size)
++              memcpy(seed->bits + EFI_RANDOM_SEED_SIZE, prev_seed->bits,
++                     prev_seed_size);
++
+       status = efi_bs_call(install_configuration_table, &rng_table_guid, seed);
+       if (status != EFI_SUCCESS)
+               goto err_freepool;
+ 
++      if (prev_seed_size) {
++              /* wipe and free the old seed if we managed to install the new one */
++              memzero_explicit(prev_seed->bits, prev_seed_size);
++              efi_bs_call(free_pool, prev_seed);
++      }
+       return EFI_SUCCESS;
+ 
+ err_freepool:
++      memzero_explicit(seed, struct_size(seed, bits, seed_size));
+       efi_bs_call(free_pool, seed);
++      efi_warn("Failed to obtain seed from EFI_RNG_PROTOCOL\n");
++err_warn:
++      if (prev_seed)
++              efi_warn("Retaining bootloader-supplied seed only");
+       return status;
+ }
+--- a/include/linux/efi.h
++++ b/include/linux/efi.h
+@@ -1170,8 +1170,6 @@ void efi_check_for_embedded_firmwares(vo
+ static inline void efi_check_for_embedded_firmwares(void) { }
+ #endif
+ 
+-efi_status_t efi_random_get_seed(void);
+-
+ #define arch_efi_call_virt(p, f, args...)     ((p)->f(args))
+ 
+ /*

diff --git a/queue-6.1/series b/queue-6.1/series
index cd7f14233b55c69bb391765ca4e27ac2c75f75d2..ee47f27574a78c14debfdba14ad9787e8439cfcb 100644 (file)
--- a/queue-6.1/series
+++ b/queue-6.1/series
@@ -155,3 +155,4 @@ ksmbd-send-proper-error-response-in-smb2_tree_connect.patch
 ksmbd-check-nt_len-to-be-at-least-cifs_encpwd_size-in-ksmbd_decode_ntlmssp_auth_blob.patch
 drm-i915-dsi-add-support-for-icl-native-mipi-gpio-sequence.patch
 drm-i915-dsi-fix-mipi_bklt_en_1-native-gpio-index.patch
+efi-random-combine-bootloader-provided-rng-seed-with-rng-protocol-output.patch