diff mbox series

[kmod,04/13] libkmod: clear file->memory if map fails

Message ID 20240212-decompression-fixes-v1-4-06f92ad07985@gmail.com (mailing list archive)
State New
Headers show
Series Load compressed modules with compression-less kmod | expand

Commit Message

Emil Velikov via B4 Relay Feb. 12, 2024, 5:23 p.m. UTC 
From: Emil Velikov <emil.l.velikov@gmail.com>

On mmap failure file->memory is set to -1, which we'll happily pass down
to munmap later on.

More importantly, since we do a NULL check in kmod_file_load_contents()
we will exit the function without (re)attempting the load again.

Since we ignore the return code for the load function(s), one can end up
calling kmod_elf_get_memory() and feed that -1 into init_module.

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
---
 libkmod/libkmod-file.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/libkmod/libkmod-file.c b/libkmod/libkmod-file.c
index abd4723..b408aed 100644
--- a/libkmod/libkmod-file.c
+++ b/libkmod/libkmod-file.c
@@ -392,8 +392,10 @@  static int load_reg(struct kmod_file *file)
 	file->size = st.st_size;
 	file->memory = mmap(NULL, file->size, PROT_READ, MAP_PRIVATE,
 			    file->fd, 0);
-	if (file->memory == MAP_FAILED)
+	if (file->memory == MAP_FAILED) {
+		file->memory = NULL;
 		return -errno;
+	}
 
 	return 0;
 }