From 506ada89629ec7059b96ecfb0dc7d33ece0103ca Mon Sep 17 00:00:00 2001 From: Eduard Zingerman Date: Fri, 4 Sep 2026 17:05:56 -0700 Subject: bpf: mark a NULL kfunc argument precise check_kfunc_arg() allows bpf_register_is_null() for nullable arguments w/o marking the underlying scalar register precise. Hence a checkpoint created on such a path would prune against arbitrary scalar value. Fixes: 3bda08b63670 ("bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)") Signed-off-by: Eduard Zingerman Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com Signed-off-by: Alexei Starovoitov --- fs/proc/util.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) create mode 100644 fs/proc/util.c (limited to 'fs/proc/util.c') diff --git a/fs/proc/util.c b/fs/proc/util.c new file mode 100644 index 000000000..98f8adc17 --- /dev/null +++ b/fs/proc/util.c @@ -0,0 +1,24 @@ +#include +#include "internal.h" + +unsigned name_to_int(const struct qstr *qstr) +{ + const char *name = qstr->name; + int len = qstr->len; + unsigned n = 0; + + if (len > 1 && *name == '0') + goto out; + do { + unsigned c = *name++ - '0'; + if (c > 9) + goto out; + if (n >= (~0U-9)/10) + goto out; + n *= 10; + n += c; + } while (--len > 0); + return n; +out: + return ~0U; +} -- cgit v1.3.1