On 24. 10. 24, 18:20, Jiri Slaby wrote:
On 12. 09. 24, 17:52, Ard Biesheuvel wrote:
From: Ard Biesheuvel <ardb@xxxxxxxxxx>
The TPM event log table is a Linux specific construct, where the data
produced by the GetEventLog() boot service is cached in memory, and
passed on to the OS using a EFI configuration table.
The use of EFI_LOADER_DATA here results in the region being left
unreserved in the E820 memory map constructed by the EFI stub, and this
is the memory description that is passed on to the incoming kernel by
kexec, which is therefore unaware that the region should be reserved.
Even though the utility of the TPM2 event log after a kexec is
questionable, any corruption might send the parsing code off into the
weeds and crash the kernel. So let's use EFI_ACPI_RECLAIM_MEMORY
instead, which is always treated as reserved by the E820 conversion
logic.
Cc: <stable@xxxxxxxxxxxxxxx>
Reported-by: Breno Leitao <leitao@xxxxxxxxxx>
Tested-by: Usama Arif <usamaarif642@xxxxxxxxx>
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
---
drivers/firmware/efi/libstub/tpm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/firmware/efi/libstub/tpm.c b/drivers/firmware/
efi/libstub/tpm.c
index df3182f2e63a..1fd6823248ab 100644
--- a/drivers/firmware/efi/libstub/tpm.c
+++ b/drivers/firmware/efi/libstub/tpm.c
@@ -96,7 +96,7 @@ static void efi_retrieve_tcg2_eventlog(int version,
efi_physical_addr_t log_loca
}
/* Allocate space for the logs and copy them. */
- status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,
+ status = efi_bs_call(allocate_pool, EFI_ACPI_RECLAIM_MEMORY,
sizeof(*log_tbl) + log_size, (void **)&log_tbl);
Hi,
this, for some reason, corrupts system configuration table. On good
boots, memattr points to 0x77535018, on bad boots (this commit applied),
it points to 0x77526018.
And the good content at 0x77526018:
tab=0x77526018 size=16+45*48=0x0000000000000880
bad content at 0x77535018:
tab=0x77535018 size=16+2*1705353216=0x00000000cb4b4010
This happens only on cold boots. Subsequent boots (having the commit or
not) are all fine.
Any ideas?
====
EFI_ACPI_RECLAIM_MEMORY
This memory is to be preserved by the UEFI OS loader and OS until ACPI
is enabled. Once ACPI is enabled, the memory in this range is available
for general use.
====
BTW doesn't the above mean it is released by the time TPM actually reads it?
Isn't the proper fix to actually memblock_reserve() that TPM portion.
The same as memattr in efi_memattr_init()?
DMI: Dell Inc. Latitude 7290/09386V, BIOS 1.39.0 07/04/2024
This was reported downstream at:
https://bugzilla.suse.com/show_bug.cgi?id=1231465
thanks,
--
js
suse labs
