lkml.org 
[lkml]   [2018]   [Sep]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] kernel/dma: Fix panic caused by passing swiotlb to command line
Date
From: He Zhe <zhe.he@windriver.com>

setup_io_tlb_npages does not check input argument before passing it
to isdigit. The argument would be a NULL pointer if "swiotlb", without
its value, is set in command line and thus causes the following panic.

PANIC: early exception 0xe3 IP 10:ffffffffbb9b8e9f error 0 cr2 0x0
[ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.0-rc3-yocto-standard+ #9
[ 0.000000] RIP: 0010:setup_io_tlb_npages+0xf/0x95
...
[ 0.000000] Call Trace:
[ 0.000000] do_early_param+0x57/0x8e
[ 0.000000] parse_args+0x208/0x320
[ 0.000000] ? rdinit_setup+0x30/0x30
[ 0.000000] parse_early_options+0x29/0x2d
[ 0.000000] ? rdinit_setup+0x30/0x30
[ 0.000000] parse_early_param+0x36/0x4d
[ 0.000000] setup_arch+0x336/0x99e
[ 0.000000] start_kernel+0x6f/0x4e6
[ 0.000000] x86_64_start_reservations+0x24/0x26
[ 0.000000] x86_64_start_kernel+0x6f/0x72
[ 0.000000] secondary_startup_64+0xa4/0xb0

This patch adds a check to prevent the panic.

Signed-off-by: He Zhe <zhe.he@windriver.com>
Cc: stable@vger.kernel.org
Cc: konrad.wilk@oracle.com
Cc: hch@lst.de
Cc: m.szyprowski@samsung.com
Cc: robin.murphy@arm.com
---
kernel/dma/swiotlb.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 4f8a6db..46fc34e 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -109,6 +109,11 @@ static int late_alloc;
static int __init
setup_io_tlb_npages(char *str)
{
+ if (!str) {
+ pr_err("Config string not provided\n");
+ return -EINVAL;
+ }
+
if (isdigit(*str)) {
io_tlb_nslabs = simple_strtoul(str, &str, 0);
/* avoid tail segment of size < IO_TLB_SEGSIZE */
--
2.7.4
\
 
 \ /
  Last update: 2018-09-17 05:28    [W:0.072 / U:0.180 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site