From bab991cf40f631d18d00cb8c2a97325c8fd4292e Mon Sep 17 00:00:00 2001 From: Gaurav Singh Date: Sat, 13 Jun 2020 21:19:40 -0400 Subject: um: Fix null pointer dereference in vector_user_bpf The bpf_prog is being checked for !NULL after uml_kmalloc but later its used directly for example: bpf_prog->filter = bpf and is also later returned upon success. Fix this, do a NULL check and return right away. Signed-off-by: Gaurav Singh Acked-By: Anton Ivanov Signed-off-by: Richard Weinberger --- arch/um/drivers/vector_user.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'arch/um') diff --git a/arch/um/drivers/vector_user.c b/arch/um/drivers/vector_user.c index c4a0f26b2824..0e6d6717bf73 100644 --- a/arch/um/drivers/vector_user.c +++ b/arch/um/drivers/vector_user.c @@ -789,10 +789,12 @@ void *uml_vector_user_bpf(char *filename) return false; } bpf_prog = uml_kmalloc(sizeof(struct sock_fprog), UM_GFP_KERNEL); - if (bpf_prog != NULL) { - bpf_prog->len = statbuf.st_size / sizeof(struct sock_filter); - bpf_prog->filter = NULL; + if (bpf_prog == NULL) { + printk(KERN_ERR "Failed to allocate bpf prog buffer"); + return NULL; } + bpf_prog->len = statbuf.st_size / sizeof(struct sock_filter); + bpf_prog->filter = NULL; ffd = os_open_file(filename, of_read(OPENFLAGS()), 0); if (ffd < 0) { printk(KERN_ERR "Error %d opening bpf file", -errno); -- cgit