[PATCH kvmtool 1/3] builtin-run: Fix warning when resolving path

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



GCC 8.2 gives this warning:

builtin-run.c: In function ‘kvm_run_write_sandbox_cmd.isra.1’:
builtin-run.c:417:28: error: ‘%s’ directive output may be truncated writing up to 4095 bytes into a region of size 4091 [-Werror=format-truncation=]
   snprintf(dst, len, "/host%s", resolved_path);
                            ^~   ~~~~~~~~~~~~~

It's because it understands that len is PATH_MAX, the same as
resolved_path's size. This patch handles the case where the string is
truncated, and fixes the warning.

Signed-off-by: Anisse Astier <aastier@xxxxxxxxxx>
---
 builtin-run.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/builtin-run.c b/builtin-run.c
index 443c10b..32d8aef 100644
--- a/builtin-run.c
+++ b/builtin-run.c
@@ -414,7 +414,9 @@ static void resolve_program(const char *src, char *dst, size_t len)
 		if (!realpath(src, resolved_path))
 			die("Unable to resolve program %s: %s\n", src, strerror(errno));
 
-		snprintf(dst, len, "/host%s", resolved_path);
+		if (snprintf(dst, len, "/host%s", resolved_path) >= (int)len - 1)
+			die("Pathname too long: %s -> %s\n", src, resolved_path);
+
 	} else
 		strncpy(dst, src, len);
 }
-- 
2.19.1




[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]

  Powered by Linux