Re: [dpdk-dev] [PATCH] eal/linux: fix uevent message parsing

[Maxime Coquelin <maxime.coquelin@redhat.com>]

On 11/2/21 19:40, David Marchand wrote:
> Caught with ASan:
> ==9727==ERROR: AddressSanitizer: stack-buffer-overflow on address
>    0x7f0daa2fc0d0 at pc 0x7f0daeefacb2 bp 0x7f0daa2fadd0 sp 0x7f0daa2fa578
> READ of size 1 at 0x7f0daa2fc0d0 thread T1
>      #0 0x7f0daeefacb1  (/lib64/libasan.so.5+0xbacb1)
>      #1 0x115eba1 in dev_uev_parse ../lib/eal/linux/eal_dev.c:167
>      #2 0x115f281 in dev_uev_handler ../lib/eal/linux/eal_dev.c:248
>      #3 0x1169b91 in eal_intr_process_interrupts
>    ../lib/eal/linux/eal_interrupts.c:1026
>      #4 0x116a3a2 in eal_intr_handle_interrupts
>    ../lib/eal/linux/eal_interrupts.c:1100
>      #5 0x116a7f0 in eal_intr_thread_main
>    ../lib/eal/linux/eal_interrupts.c:1172
>      #6 0x112640a in ctrl_thread_init
>    ../lib/eal/common/eal_common_thread.c:202
>      #7 0x7f0dade27159 in start_thread (/lib64/libpthread.so.0+0x8159)
>      #8 0x7f0dadb58f72 in clone (/lib64/libc.so.6+0xfcf72)
> 
> Address 0x7f0daa2fc0d0 is located in stack of thread T1 at offset 4192
>    in frame
>      #0 0x115f0c9 in dev_uev_handler ../lib/eal/linux/eal_dev.c:226
> 
>    This frame has 2 object(s):
>      [32, 48) 'uevent'
>      [96, 4192) 'buf' <== Memory access at offset 4192 overflows this
>    variable
> HINT: this may be a false positive if your program uses some custom
>    stack unwind mechanism or swapcontext
>        (longjmp and C++ exceptions *are* supported)
> Thread T1 created by T0 here:
>      #0 0x7f0daee92ea3 in __interceptor_pthread_create
>    (/lib64/libasan.so.5+0x52ea3)
>      #1 0x1126542 in rte_ctrl_thread_create
>    ../lib/eal/common/eal_common_thread.c:228
>      #2 0x116a8b5 in rte_eal_intr_init
>    ../lib/eal/linux/eal_interrupts.c:1200
>      #3 0x1159dd1 in rte_eal_init ../lib/eal/linux/eal.c:1044
>      #4 0x7a22f8 in main ../app/test-pmd/testpmd.c:4105
>      #5 0x7f0dada7f802 in __libc_start_main (/lib64/libc.so.6+0x23802)
> 
> Signed-off-by: David Marchand <david.marchand@redhat.com>
> ---
>   lib/eal/linux/eal_dev.c | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/lib/eal/linux/eal_dev.c b/lib/eal/linux/eal_dev.c
> index 925cdba553..1fd00a482b 100644
> --- a/lib/eal/linux/eal_dev.c
> +++ b/lib/eal/linux/eal_dev.c
> @@ -160,6 +160,9 @@ dev_uev_parse(const char *buf, struct rte_dev_event *event, int length)
>   				break;
>   			buf++;
>   		}
> +		if (i >= length)
> +			break;
> +
>   		/**
>   		 * check device uevent from kernel side, no need to check
>   		 * uevent from udev.
> 

Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

Thanks,
Maxime