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authorAnton Gusev <aagusev@ispras.ru>2023-02-03 16:22:13 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-02-09 13:28:11 +0300
commita2e6a9ff89f13666a1c3ff7195612ab949ea9afc (patch)
treeb8c3cd5909f1b3dc139f34f175b8eba474d52a16 /drivers/firmware
parent70d40674a549d498bd63d5432acf46205da1534b (diff)
downloadlinux-a2e6a9ff89f13666a1c3ff7195612ab949ea9afc.tar.xz
efi: fix potential NULL deref in efi_mem_reserve_persistent
[ Upstream commit 966d47e1f27c45507c5df82b2a2157e5a4fd3909 ] When iterating on a linked list, a result of memremap is dereferenced without checking it for NULL. This patch adds a check that falls back on allocating a new page in case memremap doesn't succeed. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 18df7577adae ("efi/memreserve: deal with memreserve entries in unmapped memory") Signed-off-by: Anton Gusev <aagusev@ispras.ru> [ardb: return -ENOMEM instead of breaking out of the loop] Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/firmware')
-rw-r--r--drivers/firmware/efi/efi.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 033aac6be7da..b43e5e6ddaf6 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -984,6 +984,8 @@ int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
/* first try to find a slot in an existing linked list entry */
for (prsv = efi_memreserve_root->next; prsv; ) {
rsv = memremap(prsv, sizeof(*rsv), MEMREMAP_WB);
+ if (!rsv)
+ return -ENOMEM;
index = atomic_fetch_add_unless(&rsv->count, 1, rsv->size);
if (index < rsv->size) {
rsv->entry[index].base = addr;