iommu.lists.linux-foundation.org archive mirror
 help / color / mirror / Atom feed
* [PATCH] kernel/dma: Fix panic caused by passing swiotlb to command line
@ 2018-09-17  3:27 zhe.he
       [not found] ` <1537154831-447363-1-git-send-email-zhe.he-CWA4WttNNZF54TAoqtyWWQ@public.gmane.org>
  0 siblings, 1 reply; 7+ messages in thread
From: zhe.he @ 2018-09-17  3:27 UTC (permalink / raw)
  To: konrad.wilk, hch, m.szyprowski, robin.murphy, iommu, linux-kernel; +Cc: zhe.he

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

^ permalink raw reply related	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2018-12-03 10:20 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2018-09-17  3:27 [PATCH] kernel/dma: Fix panic caused by passing swiotlb to command line zhe.he
     [not found] ` <1537154831-447363-1-git-send-email-zhe.he-CWA4WttNNZF54TAoqtyWWQ@public.gmane.org>
2018-09-22 12:56   ` He Zhe
2018-10-22 19:29     ` Konrad Rzeszutek Wilk
     [not found]       ` <20181022192921.GA20677-opBMJL+S1+nQ9WkVDsLzkxXsgy71PS11DgX97ZZ8RBg@public.gmane.org>
2018-10-23 11:14         ` He Zhe
2018-10-30 11:06           ` He Zhe
2018-12-02 12:30             ` Konrad Rzeszutek Wilk
     [not found]               ` <20181202123032.GA3166-bi+AKbBUZKY6gyzm1THtWbp2dZbC/Bob@public.gmane.org>
2018-12-03 10:20                 ` He Zhe

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).