summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorZbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>2016-08-11 04:51:00 -0400
committerLennart Poettering <lennart@poettering.net>2016-08-11 10:51:00 +0200
commit6998b54093831fac92e2b1e251659e64d56e1df6 (patch)
tree99868461576e4753de4f36527064883a8239235b
parentff0bb1ed93fb80cdc2b456894e0d1567ddd97bdc (diff)
coredump: treat RLIMIT_CORE below page size as disabling coredumps (#3932)
The kernel treats values below a certain threshold (minfmt->min_coredump which is initialized do ELF_EXEC_PAGESIZE, which varies between architectures, but is usually the same as PAGE_SIZE) as disabling coredumps [1]. Any core image below ELF_EXEC_PAGESIZE will yield an invalid backtrace anyway [2], so follow the kernel and not try to parse or store such images. [1] https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/fs/coredump.c#n660 [2] systemd-coredump[16260]: Process 16258 (sleep) of user 1002 dumped core. Stack trace of thread 16258: #0 0x00007f1d8b3d3810 n/a (n/a) https://bugzilla.redhat.com/show_bug.cgi?id=1309172#c19
-rw-r--r--src/coredump/coredump.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/src/coredump/coredump.c b/src/coredump/coredump.c
index e3d17c864d..be724aed4e 100644
--- a/src/coredump/coredump.c
+++ b/src/coredump/coredump.c
@@ -327,9 +327,11 @@ static int save_external_coredump(
r = safe_atou64(context[CONTEXT_RLIMIT], &rlimit);
if (r < 0)
return log_error_errno(r, "Failed to parse resource limit: %s", context[CONTEXT_RLIMIT]);
- if (rlimit <= 0) {
- /* Is coredumping disabled? Then don't bother saving/processing the coredump */
- log_info("Core Dumping has been disabled for process %s (%s).", context[CONTEXT_PID], context[CONTEXT_COMM]);
+ if (rlimit < page_size()) {
+ /* Is coredumping disabled? Then don't bother saving/processing the coredump.
+ * Anything below PAGE_SIZE cannot give a readable coredump (the kernel uses
+ * ELF_EXEC_PAGESIZE which is not easily accessible, but is usually the same as PAGE_SIZE. */
+ log_info("Core dumping has been disabled for process %s (%s).", context[CONTEXT_PID], context[CONTEXT_COMM]);
return -EBADSLT;
}