From 6038aa532a224da68c478f34f4dbce33c47169e6 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 12 Apr 2018 09:16:07 -0600 Subject: [PATCH] nvme: target: fix buffer overflow nvmet_execute_get_disc_log_page() passes a fixed-length string into nvmet_format_discovery_entry(), which then does a longer memcpy() on it, as pointed out by gcc-8: In function 'nvmet_format_discovery_entry', inlined from 'nvmet_execute_get_disc_log_page' at drivers/nvme/target/discovery.c:126:4: drivers/nvme/target/discovery.c:62:2: error: 'memcpy' forming offset [38, 223] is out of the bounds [0, 37] [-Werror=array-bounds] memcpy(e->subnqn, subsys_nqn, NVMF_NQN_SIZE); Using strncpy() will make this well-defined, filling the rest of the buffer with zeroes, under the assumption that the input is either a NUL-terminated string, or a byte sequence containing no zeroes. If the input is a string that is longer than NVMF_NQN_SIZE, we continue to have no NUL-termination in the output. Fixes: a07b4970f464 ("nvmet: add a generic NVMe target") Signed-off-by: Arnd Bergmann Reviewed-by: Christoph Hellwig Signed-off-by: Keith Busch Signed-off-by: Jens Axboe --- drivers/nvme/target/discovery.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/nvme/target/discovery.c b/drivers/nvme/target/discovery.c index a72425d8bce0..231e04e0a496 100644 --- a/drivers/nvme/target/discovery.c +++ b/drivers/nvme/target/discovery.c @@ -59,7 +59,7 @@ static void nvmet_format_discovery_entry(struct nvmf_disc_rsp_page_hdr *hdr, memcpy(e->trsvcid, port->disc_addr.trsvcid, NVMF_TRSVCID_SIZE); memcpy(e->traddr, traddr, NVMF_TRADDR_SIZE); memcpy(e->tsas.common, port->disc_addr.tsas.common, NVMF_TSAS_SIZE); - memcpy(e->subnqn, subsys_nqn, NVMF_NQN_SIZE); + strncpy(e->subnqn, subsys_nqn, NVMF_NQN_SIZE); } /* -- 2.30.2