From 618ab2e3c1ee713517b881b5038a9a1cef51aa7f Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Tue, 10 Dec 2019 10:09:45 +0100 Subject: [PATCH] efi: Don't attempt to map RCI2 config table if it doesn't exist [ Upstream commit a470552ee8965da0fe6fd4df0aa39c4cda652c7c ] Commit: 1c5fecb61255aa12 ("efi: Export Runtime Configuration Interface table to sysfs") ... added support for a Dell specific UEFI configuration table, but failed to take into account that mapping the table should not be attempted unless the table actually exists. If it doesn't exist, the code usually fails silently unless pr_debug() prints are enabled. However, on 32-bit PAE x86, the splat below is produced due to the attempt to map the placeholder value EFI_INVALID_TABLE_ADDR which we use for non-existing UEFI configuration tables, and which equals ULONG_MAX. memremap attempted on mixed range 0x00000000ffffffff size: 0x1e WARNING: CPU: 1 PID: 1 at kernel/iomem.c:81 memremap+0x1a3/0x1c0 Modules linked in: CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.4.2-smp-mine #1 Hardware name: Hewlett-Packard HP Z400 Workstation/0B4Ch, BIOS 786G3 v03.61 03/05/2018 EIP: memremap+0x1a3/0x1c0 ... Call Trace: ? map_properties+0x473/0x473 ? efi_rci2_sysfs_init+0x2c/0x154 ? map_properties+0x473/0x473 ? do_one_initcall+0x49/0x1d4 ? parse_args+0x1e8/0x2a0 ? do_early_param+0x7a/0x7a ? kernel_init_freeable+0x139/0x1c2 ? rest_init+0x8e/0x8e ? kernel_init+0xd/0xf2 ? ret_from_fork+0x2e/0x38 Fix this by checking whether the table exists before attempting to map it. Reported-by: Richard Narron Tested-by: Richard Narron Signed-off-by: Ard Biesheuvel Cc: linux-efi@vger.kernel.org Fixes: 1c5fecb61255aa12 ("efi: Export Runtime Configuration Interface table to sysfs") Link: https://lkml.kernel.org/r/20191210090945.11501-2-ardb@kernel.org Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin --- drivers/firmware/efi/rci2-table.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/firmware/efi/rci2-table.c b/drivers/firmware/efi/rci2-table.c index 76b0c354a027..de1a9a1f9f14 100644 --- a/drivers/firmware/efi/rci2-table.c +++ b/drivers/firmware/efi/rci2-table.c @@ -81,6 +81,9 @@ static int __init efi_rci2_sysfs_init(void) struct kobject *tables_kobj; int ret = -ENOMEM; + if (rci2_table_phys == EFI_INVALID_TABLE_ADDR) + return 0; + rci2_base = memremap(rci2_table_phys, sizeof(struct rci2_table_global_hdr), MEMREMAP_WB);