From 61ed56090c52d7617e5e8f4b30c88424d20268da Mon Sep 17 00:00:00 2001 From: Luca Ceresoli Date: Fri, 19 Aug 2016 15:52:53 +0200 Subject: [PATCH] busybox: fix double free in top causing a SIGABRT storm after SIGPIPE On some platforms the command 'top -n1 | head' goes very often into an infinite loop of SIGABRT and double free()s. Fix by applying a patch from upstream Busybox. For a detailed explanation of the bug, see http://lists.busybox.net/pipermail/busybox/2016-August/084555.html Thanks to Yann for the help in finding this bug. Signed-off-by: Luca Ceresoli Cc: "Yann E. MORIN" Signed-off-by: Thomas Petazzoni --- ...ve-free-prev_hist-out-of-signal-path.patch | 48 +++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 package/busybox/0006-top-move-free-prev_hist-out-of-signal-path.patch diff --git a/package/busybox/0006-top-move-free-prev_hist-out-of-signal-path.patch b/package/busybox/0006-top-move-free-prev_hist-out-of-signal-path.patch new file mode 100644 index 0000000000..f5e2942013 --- /dev/null +++ b/package/busybox/0006-top-move-free-prev_hist-out-of-signal-path.patch @@ -0,0 +1,48 @@ +From aedc3fe19fac368dc363050e0387d263b7e01cc6 Mon Sep 17 00:00:00 2001 +From: Denys Vlasenko +Date: Fri, 19 Aug 2016 11:07:31 +0200 +Subject: [PATCH] top: move free(prev_hist) out of signal path + +It was seen being called recursively on repeated signals, +leading to double free + +Signed-off-by: Denys Vlasenko +Backported-from: https://git.busybox.net/busybox/commit/?id=aedc3fe19fac368dc363050e0387d263b7e01cc6 +Signed-off-by: Luca Ceresoli + +--- + procps/top.c | 12 ++++++------ + 1 file changed, 6 insertions(+), 6 deletions(-) + +diff --git a/procps/top.c b/procps/top.c +index 73cd285..6f7f7d3 100644 +--- a/procps/top.c ++++ b/procps/top.c +@@ -728,12 +728,6 @@ static void reset_term(void) + { + if (!OPT_BATCH_MODE) + tcsetattr_stdin_TCSANOW(&initial_settings); +- if (ENABLE_FEATURE_CLEAN_UP) { +- clearmems(); +-# if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE +- free(prev_hist); +-# endif +- } + } + + static void sig_catcher(int sig) +@@ -1258,5 +1252,11 @@ int top_main(int argc UNUSED_PARAM, char **argv) + #if ENABLE_FEATURE_USE_TERMIOS + reset_term(); + #endif ++ if (ENABLE_FEATURE_CLEAN_UP) { ++ clearmems(); ++#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE ++ free(prev_hist); ++#endif ++ } + return EXIT_SUCCESS; + } +-- +2.7.4 + -- 2.30.2