Re: [Buildroot] [PATCH v3 1/3] package/makedevs: allow recursive on directory with dangling symlinks

["Yann E. MORIN" <yann.morin.1998@free.fr>]

Joachim, All,

On 2021-12-23 10:07 +0100, Joachim Wiberg spake thusly:
> When using BR2_ROOTFS_DEVICE_TABLE to change ownership of /etc, like so:
> 
>   /etc        r  -1 root     wheel     - - - - -
> 
> makdevs fails due to it trying to chown() a dangling symlink:

*makedevs   *its (really "its", and really not "it's")

Applied to master, thanks.

Regards,
Yann E. MORIN.

>   makedevs: chown failed for /src/myLinux/output/build/buildroot-fs/ext2/target/etc/mtab: No such file or directory
>   makedevs: line 25: recursive failed for /src/myLinux/output/build/buildroot-fs/ext2/target/etc: No such file or directory
>   make[2]: *** [fs/ext2/ext2.mk:63: /src/myLinux/output/images/rootfs.ext2] Error 1
>   make[1]: *** [Makefile:84: _all] Error 2
>   make[1]: Leaving directory '/src/myLinux/buildroot'
> 
> This patch changes chown() to lchown() in two cases in makedevs.c when
> the argument can be a symlink, dangling or not.
> 
> In case the recursive operation includes a chmod() as well, explicitly
> exclude symlinks that are dangling, because chmod() always operates on
> the link target.
> 
> Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
> ---
>  package/makedevs/makedevs.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/package/makedevs/makedevs.c b/package/makedevs/makedevs.c
> index c57b964f5c..2796cd5e78 100644
> --- a/package/makedevs/makedevs.c
> +++ b/package/makedevs/makedevs.c
> @@ -440,11 +440,13 @@ void bb_show_usage(void)
>  int bb_recursive(const char *fpath, const struct stat *sb,
>  		int tflag, struct FTW *ftwbuf){
>  
> -	if (chown(fpath, recursive_uid, recursive_gid) == -1) {
> +	if (lchown(fpath, recursive_uid, recursive_gid) == -1) {
>  		bb_perror_msg("chown failed for %s", fpath);
>  		return -1;
>  	}
> -	if (recursive_mode != -1) {
> +
> +	/* chmod() is optional, also skip if dangling symlink */
> +	if (recursive_mode != -1 && tflag == FTW_SL && access(fpath, F_OK)) {
>  		if (chmod(fpath, recursive_mode) < 0) {
>  			bb_perror_msg("chmod failed for %s", fpath);
>  			return -1;
> @@ -628,7 +630,7 @@ int main(int argc, char **argv)
>  				if (mknod(full_name_inc, mode, rdev) < 0) {
>  					bb_perror_msg("line %d: can't create node %s", linenum, full_name_inc);
>  					ret = EXIT_FAILURE;
> -				} else if (chown(full_name_inc, uid, gid) < 0) {
> +				} else if (lchown(full_name_inc, uid, gid) < 0) {
>  					bb_perror_msg("line %d: can't chown %s", linenum, full_name_inc);
>  					ret = EXIT_FAILURE;
>  				} else if (chmod(full_name_inc, mode) < 0) {
> -- 
> 2.25.1
> 
> _______________________________________________
> buildroot mailing list
> buildroot@buildroot.org
> https://lists.buildroot.org/mailman/listinfo/buildroot

-- 
.-----------------.--------------------.------------------.--------------------.
|  Yann E. MORIN  | Real-Time Embedded | /"\ ASCII RIBBON | Erics' conspiracy: |
| +33 662 376 056 | Software  Designer | \ / CAMPAIGN     |  ___               |
| +33 561 099 427 `------------.-------:  X  AGAINST      |  \e/  There is no  |
| http://ymorin.is-a-geek.org/ | _/*\_ | / \ HTML MAIL    |   v   conspiracy.  |
'------------------------------^-------^------------------^--------------------'
_______________________________________________
buildroot mailing list
buildroot@buildroot.org
https://lists.buildroot.org/mailman/listinfo/buildroot