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| author | Gaurav Singh <gaurav1086@gmail.com> | 2020-06-13 21:19:40 -0400 |
|---|---|---|
| committer | Richard Weinberger <richard@nod.at> | 2020-10-11 23:12:51 +0200 |
| commit | bab991cf40f631d18d00cb8c2a97325c8fd4292e (patch) | |
| tree | e9a621e1d6e042925c4ed29e50a815634d29af2f | |
| parent | ba4f184e126b751d1bffad5897f263108befc780 (diff) | |
| download | lwn-bab991cf40f631d18d00cb8c2a97325c8fd4292e.tar.gz lwn-bab991cf40f631d18d00cb8c2a97325c8fd4292e.zip | |
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 <gaurav1086@gmail.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
| -rw-r--r-- | arch/um/drivers/vector_user.c | 8 |
1 files changed, 5 insertions, 3 deletions
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); |