Re: [PATCH dwarves v3 3/5] btf_encoder: explicitly check addr/size for u32 overflow

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 03/10/2024 00:52, Stephen Brennan wrote:
> The addr is a uint64_t, and depending on the size of a data section,
> there's no guarantee that it fits into a uint32_t, even after
> subtracting out the section start address. Similarly, the variable size
> is a size_t which could exceed a uint32_t. Check both for overflow, and
> if found, skip the variable with an error message. Use explicit casts
> when we cast to uint32_t so it's plain to see that this is happening.
> 
> Signed-off-by: Stephen Brennan <stephen.s.brennan@xxxxxxxxxx>

Reviewed-by: Alan Maguire <alan.maguire@xxxxxxxxxx>

> ---
>  btf_encoder.c | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/btf_encoder.c b/btf_encoder.c
> index 31a418a..1872e00 100644
> --- a/btf_encoder.c
> +++ b/btf_encoder.c
> @@ -2250,9 +2250,16 @@ static int btf_encoder__encode_cu_variables(struct btf_encoder *encoder)
>  
>  		tag = cu__type(cu, var->ip.tag.type);
>  		size = tag__size(tag, cu);
> -		if (size == 0) {
> +		if (size == 0 || size > UINT32_MAX) {
>  			if (encoder->verbose)
> -				fprintf(stderr, "Ignoring zero-sized per-CPU variable '%s'...\n", name);
> +				fprintf(stderr, "Ignoring %s-sized per-CPU variable '%s'...\n",
> +					size == 0 ? "zero" : "over", name);
> +			continue;
> +		}
> +		if (addr > UINT32_MAX) {
> +			if (encoder->verbose)
> +				fprintf(stderr, "Ignoring variable '%s' - its offset %zu doesn't fit in a u32\n",
> +					name, addr);
>  			continue;
>  		}
>  
> @@ -2285,7 +2292,7 @@ static int btf_encoder__encode_cu_variables(struct btf_encoder *encoder)
>  		 * add a BTF_VAR_SECINFO in encoder->percpu_secinfo, which will be added into
>  		 * encoder->types later when we add BTF_VAR_DATASEC.
>  		 */
> -		id = btf_encoder__add_var_secinfo(encoder, id, addr, size);
> +		id = btf_encoder__add_var_secinfo(encoder, id, (uint32_t)addr, (uint32_t)size);
>  		if (id < 0) {
>  			fprintf(stderr, "error: failed to encode section info for variable '%s' at addr 0x%" PRIx64 "\n",
>  			        name, addr);





[Index of Archives]     [Linux Samsung SoC]     [Linux Rockchip SoC]     [Linux Actions SoC]     [Linux for Synopsys ARC Processors]     [Linux NFS]     [Linux NILFS]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]


  Powered by Linux