On Thu, Jun 19, 2025 at 09:10:30AM +0200, David Marchand wrote:
> For '.' and '..' directories (or any short file name),
> a out of bound issue occurs.
> 
> Caught by UBSan:
> 
> EAL: Detected shared linkage of DPDK
> ../lib/eal/common/eal_common_options.c:420:15: runtime error: index -2
>       out of bounds for type 'char[256]'
>     #0 0x7f867eedf206 in eal_plugindir_init
>       eal_common_options.c
>     #1 0x7f867eede58a in eal_plugins_init
>       (build/lib/librte_eal.so.25+0xde58a)
>       (BuildId: e7e4a1935e4bacb51c82ab1a84098a27decf3b4c)
>     #2 0x7f867efb8587 in rte_eal_init
>       (build/lib/librte_eal.so.25+0x1b8587)
>       (BuildId: e7e4a1935e4bacb51c82ab1a84098a27decf3b4c)
>     #3 0x55b62360861e in main
>       (/home/runner/work/dpdk/dpdk/build/app/dpdk-testpmd+0x9e061e)
>       (BuildId: d821ec918612c83fad8b5ccb6cc518e66bee48cd)
>     #4 0x7f8667429d8f in __libc_start_call_main
>       csu/../sysdeps/nptl/libc_start_call_main.h:58:16
>     #5 0x7f8667429e3f in __libc_start_main
>       csu/../csu/libc-start.c:392:3
>     #6 0x55b622d9d444 in _start
>       (/home/runner/work/dpdk/dpdk/build/app/dpdk-testpmd+0x175444)
>       (BuildId: d821ec918612c83fad8b5ccb6cc518e66bee48cd)
> SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior
>       ../lib/eal/common/eal_common_options.c:420:15 in
>       ../lib/eal/common/eal_common_options.c:421:15:
>       runtime error: index 18446744073709551609 out of bounds
>       for type 'char[256]'
> 
> Fixes: c57f6e5c604a ("eal: fix plugin loading")
> Cc: sta...@dpdk.org
> 
> Signed-off-by: David Marchand <david.march...@redhat.com>
> ---
Acked-by: Bruce Richardson <bruce.richard...@intel.com>

One thought inline below...

>  lib/eal/common/eal_common_options.c | 15 +++++++++++----
>  1 file changed, 11 insertions(+), 4 deletions(-)
> 
> diff --git a/lib/eal/common/eal_common_options.c 
> b/lib/eal/common/eal_common_options.c
> index 83b6fc7e89..153f807e4f 100644
> --- a/lib/eal/common/eal_common_options.c
> +++ b/lib/eal/common/eal_common_options.c
> @@ -399,6 +399,14 @@ eal_plugins_init(void)
>  }
>  #else
>  
> +static bool
> +ends_with(const char *str, size_t str_len, const char *tail)
> +{
> +     size_t tail_len = strlen(tail);
> +
> +     return str_len >= tail_len && strncmp(&str[str_len - tail_len], tail, 
> tail_len) == 0;
> +}
> +

I wonder if that function is worth renaming to "rte_str_ends_with" and
putting in rte_string_fns.h?


>  static int
>  eal_plugindir_init(const char *path)
>  {
> @@ -417,13 +425,12 @@ eal_plugindir_init(const char *path)
>       }
>  
>       while ((dent = readdir(d)) != NULL) {
> +             size_t nlen = strnlen(dent->d_name, sizeof(dent->d_name));
>               struct stat sb;
> -             int nlen = strnlen(dent->d_name, sizeof(dent->d_name));
>  
>               /* check if name ends in .so or .so.ABI_VERSION */
> -             if (strcmp(&dent->d_name[nlen - 3], ".so") != 0 &&
> -                 strcmp(&dent->d_name[nlen - 4 - strlen(ABI_VERSION)],
> -                        ".so."ABI_VERSION) != 0)
> +             if (!ends_with(dent->d_name, nlen, ".so") &&
> +                             !ends_with(dent->d_name, nlen, 
> ".so."ABI_VERSION))
>                       continue;
>  
>               snprintf(sopath, sizeof(sopath), "%s/%s", path, dent->d_name);
> -- 
> 2.49.0
> 

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