Commit 4720f970 authored by David Wei's avatar David Wei Committed by Jakub Kicinski
Browse files

tools: ynl-gen: validate 0 len strings from kernel 



Strings from the kernel are guaranteed to be null terminated and
ynl_attr_validate() checks for this. But it doesn't check if the string
has a len of 0, which would cause problems when trying to access
data[len - 1]. Fix this by checking that len is positive.

Signed-off-by: default avatarDavid Wei <dw@davidwei.uk>
Link: https://patch.msgid.link/20250503043050.861238-1-dw@davidwei.uk


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent c645a6b2

tools/net/ynl/lib/ynl.c

+1 −1
Original line number Diff line number Diff line
@@ -364,7 +364,7 @@ int ynl_attr_validate(struct ynl_parse_arg *yarg, const struct nlattr *attr) 
		     "Invalid attribute (binary %s)", policy->name);

		return -1;

	case YNL_PT_NUL_STR:

		if ((!policy->len || len <= policy->len) && !data[len - 1])

		if (len && (!policy->len || len <= policy->len) && !data[len - 1])

			break;

		yerr(yarg->ys, YNL_ERROR_ATTR_INVALID,

		     "Invalid attribute (string %s)", policy->name);