diff options
| author | He Zhe <zhe.he@windriver.com> | 2018-09-17 05:24:20 +0200 |
|---|---|---|
| committer | Christoph Hellwig <hch@lst.de> | 2018-09-20 09:01:08 +0200 |
| commit | a3ceed87b07769fb80ce9dc6b604e515dba14c4b (patch) | |
| tree | c3101cb16ad2bd622540a50879b9ca33f714a7f2 | |
| parent | dma-mapping: clear dev->dma_ops in arch_teardown_dma_ops (diff) | |
| download | linux-a3ceed87b07769fb80ce9dc6b604e515dba14c4b.tar.xz linux-a3ceed87b07769fb80ce9dc6b604e515dba14c4b.zip | |
dma-mapping: fix panic caused by passing empty cma command line argument
early_cma does not check input argument before passing it to
simple_strtoull. The argument would be a NULL pointer if "cma", without
its value, is set in command line and thus causes the following panic.
PANIC: early exception 0xe3 IP 10:ffffffffa3e9db8d error 0 cr2 0x0
[ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.0-rc3-yocto-standard+ #7
[ 0.000000] RIP: 0010:_parse_integer_fixup_radix+0xd/0x70
...
[ 0.000000] Call Trace:
[ 0.000000] simple_strtoull+0x29/0x70
[ 0.000000] memparse+0x26/0x90
[ 0.000000] early_cma+0x17/0x6a
[ 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>
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: stable@vger.kernel.org
Signed-off-by: Christoph Hellwig <hch@lst.de>
| -rw-r--r-- | kernel/dma/contiguous.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c index 286d82329eb0..b2a87905846d 100644 --- a/kernel/dma/contiguous.c +++ b/kernel/dma/contiguous.c @@ -49,7 +49,11 @@ static phys_addr_t limit_cmdline; static int __init early_cma(char *p) { - pr_debug("%s(%s)\n", __func__, p); + if (!p) { + pr_err("Config string not provided\n"); + return -EINVAL; + } + size_cmdline = memparse(p, &p); if (*p != '@') return 0; |