On Mon, Feb 12, 2024 at 05:23:05PM GMT, Emil Velikov via B4 Relay wrote:
From: Emil Velikov <emil.l.velikov@xxxxxxxxx> 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@xxxxxxxxx>
Reviewed-by: Lucas De Marchi <lucas.demarchi@xxxxxxxxx> Lucas De Marchi
--- libkmod/libkmod-file.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) 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; } -- 2.43.0