mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-08-28 01:43:47 -04:00
Code Issues Packages Projects Releases Wiki Activity

bpftool: Fix double close in map dump

Browse Source 
map_dump() closes the map fd in its error path, and do_dump() then
closes the same fd again after a successful dump. Closing an already
closed fd leaves errno set to EBADF, which poisons later errno checks
such as the batch file read check in do_batch(). Let do_dump() own the
fd and remove the close from map_dump().

The same double-close pattern exists in do_show_subset(): both
show_map_close_json() and show_map_close_plain() already close the fd,
so drop the extra close() there as well.

Also propagate the error when bpf_map_get_info_by_fd() fails on a
subsequent map in do_dump(): set err = -1 before breaking out of the
loop, so a later failure is not silently hidden after an earlier
iteration succeeded.

Fixes: 99f9863a0c ("bpftool: Match maps by name")
Signed-off-by: Yuan Chen <chenyuan@kylinos.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260810142224.2907373-2-chenyuan_fl@163.com
This commit is contained in:
Yuan Chen
2026-08-10 22:22:22 +08:00
committed by Andrii Nakryiko
parent aacd13e1eb
commit 259d60f5bf
1 changed files with 1 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
tools/bpf/bpftool/map.c
View File

@@ -659,8 +659,6 @@ static int do_show_subset(int argc, char **argv)
show_map_close_json(fds[i], &info);
else
show_map_close_plain(fds[i], &info);
close(fds[i]);
}
if (json_output && nb_fds > 1)
jsonw_end_array(json_wtr); /* root array */
@@ -895,7 +893,6 @@ map_dump(int fd, struct bpf_map_info *info, json_writer_t *wtr,
exit_free:
free(key);
free(value);
close(fd);
free_map_kv_btf(btf);
return err;
@@ -944,6 +941,7 @@ static int do_dump(int argc, char **argv)
for (i = 0; i < nb_fds; i++) {
if (bpf_map_get_info_by_fd(fds[i], &info, &len)) {
p_err("can't get map info: %s", strerror(errno));
err = -1;
break;
}
err = map_dump(fds[i], &info, wtr, nb_fds > 1);