split_huge_pages_write does not handle the case where strsep finds no delimiter in the given string and sets the input buffer to NULL, which allows this reproducer to trigger a protection fault. Reported-by: syzbot+8a3da2f1bbf59227c289@xxxxxxxxxxxxxxxxxxxxxxxxx Closes: https://syzkaller.appspot.com/bug?extid=8a3da2f1bbf59227c289 Signed-off-by: Leo Stone <leocstone@xxxxxxxxx> --- mm/huge_memory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index ee335d96fc39..361319f749f0 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -4168,7 +4168,7 @@ static ssize_t split_huge_pages_write(struct file *file, const char __user *buf, size_t input_len = strlen(input_buf); tok = strsep(&buf, ","); - if (tok) { + if (tok && buf) { strscpy(file_path, tok); } else { ret = -EINVAL; -- 2.43.0
