This is a note to let you know that I've just added the patch titled
firmware/efi: Fix a use after bug in efi_mem_reserve_persistent
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
firmware-efi-fix-a-use-after-bug-in-efi_mem_reserve_persistent.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 9ceee7d0841a8f7d7644021ba7d4cc1fbc7966e3 Mon Sep 17 00:00:00 2001
From: Lv Yunlong <lyl2019@xxxxxxxxxxxxxxxx>
Date: Wed, 10 Mar 2021 00:31:27 -0800
Subject: firmware/efi: Fix a use after bug in efi_mem_reserve_persistent
From: Lv Yunlong <lyl2019@xxxxxxxxxxxxxxxx>
commit 9ceee7d0841a8f7d7644021ba7d4cc1fbc7966e3 upstream.
In the for loop in efi_mem_reserve_persistent(), prsv = rsv->next
use the unmapped rsv. Use the unmapped pages will cause segment
fault.
Fixes: 18df7577adae6 ("efi/memreserve: deal with memreserve entries in unmapped memory")
Signed-off-by: Lv Yunlong <lyl2019@xxxxxxxxxxxxxxxx>
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/firmware/efi/efi.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -927,7 +927,7 @@ int __ref efi_mem_reserve_persistent(phy
}
/* first try to find a slot in an existing linked list entry */
- for (prsv = efi_memreserve_root->next; prsv; prsv = rsv->next) {
+ for (prsv = efi_memreserve_root->next; prsv; ) {
rsv = memremap(prsv, sizeof(*rsv), MEMREMAP_WB);
index = atomic_fetch_add_unless(&rsv->count, 1, rsv->size);
if (index < rsv->size) {
@@ -937,6 +937,7 @@ int __ref efi_mem_reserve_persistent(phy
memunmap(rsv);
return efi_mem_reserve_iomem(addr, size);
}
+ prsv = rsv->next;
memunmap(rsv);
}
Patches currently in stable-queue which might be from lyl2019@xxxxxxxxxxxxxxxx are
queue-5.10/scsi-myrs-fix-a-double-free-in-myrs_cleanup.patch
queue-5.10/firmware-efi-fix-a-use-after-bug-in-efi_mem_reserve_persistent.patch
