From 23db6896830d6b37fc3bcc3ad5a7f725eb97d2e1 Mon Sep 17 00:00:00 2001 From: Hajime Tazaki Date: Mon, 25 Nov 2024 14:08:36 +0900 Subject: hush: fix G.argv0_for_re_execing to avoid endless loop When the busybox is used as /sbin/init and the inittab file contains below: ::respawn:-/bin/sh /sbin/init spawns hush for the first time with the argv[0] contains '-', and hush treats it as login shell. Then it reads /etc/profile and if the file contains the command execution like below, it invokes hush as login shell because the argv[0] argument is still '-/bin/sh' and reads /etc/profile again. This will last until some failure (e.g., memory failure) happens. [ "$(id -u)" -eq 0 ] && PS1="${PS1}# " || PS1="${PS1}\$ " This commit fixes this issues by adding an offset (+1) to the G.argv0_for_re_execing variable. This issue happens on our out-of-tree UML (use mode linux) with nommu configuration. Link: https://lore.kernel.org/all/cover.1731290567.git.thehajime@gmail.com/ Signed-off-by: Hajime Tazaki Signed-off-by: Denys Vlasenko --- shell/hush.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/shell/hush.c b/shell/hush.c index 04dda0734..4a97293cc 100644 --- a/shell/hush.c +++ b/shell/hush.c @@ -10361,6 +10361,9 @@ int hush_main(int argc, char **argv) _exit(0); } G.argv0_for_re_execing = argv[0]; + if (G.argv0_for_re_execing[0] == '-') + /* reexeced hush should never be a login shell */ + G.argv0_for_re_execing++; #endif #if ENABLE_HUSH_TRAP # if ENABLE_HUSH_FUNCTIONS -- cgit v1.2.3-55-g6feb