From 300a1f53907a4acaadd9a696d0c67eee6fc10430 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Sat, 31 Aug 2024 12:25:44 -0400 Subject: [PATCH 1/2] sigaltstack: enforce dynamic MINSIGSTKSZ limit commit 996b6154b20184c3b08cce28eb01edb7f47e9413 added support for querying the dynamic limit but did not enforce it in sigaltstack. the kernel also does not seem to reliably enforce it, or at least does not necessarily enforce the same limit exposed to userspace, so it needs to be enforced here. --- src/signal/sigaltstack.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/src/signal/sigaltstack.c b/src/signal/sigaltstack.c index d3a6e821..616625c5 100644 --- a/src/signal/sigaltstack.c +++ b/src/signal/sigaltstack.c @@ -1,11 +1,13 @@ #include #include +#include #include "syscall.h" int sigaltstack(const stack_t *restrict ss, stack_t *restrict old) { if (ss) { - if (!(ss->ss_flags & SS_DISABLE) && ss->ss_size < MINSIGSTKSZ) { + size_t min = sysconf(_SC_MINSIGSTKSZ); + if (!(ss->ss_flags & SS_DISABLE) && ss->ss_size < min) { errno = ENOMEM; return -1; } -- 2.21.0