On Mon, Nov 21, 2016 at 11:25 AM, Miroslav Benes <[email protected]> wrote: > On Mon, 21 Nov 2016, Dmitry Vyukov wrote: > >> WARNINGs mean kernel bugs. >> The one in ucma_write() points to user programming error >> or a malicious attempt. This is not a kernel bug, remove it. >> >> BUG/WARNs that are not kernel bugs hinder automated testing effots. >> >> Signed-off-by: Dmitry Vyukov <[email protected]> >> Cc: Doug Ledford <[email protected]> >> Cc: Sean Hefty <[email protected]> >> Cc: Hal Rosenstock <[email protected]> >> Cc: Leon Romanovsky <[email protected]> >> Cc: [email protected] >> Cc: [email protected] >> Cc: [email protected] >> >> --- >> Changes since v1: >> - added printk_once >> --- >> drivers/infiniband/core/ucma.c | 5 ++++- >> 1 file changed, 4 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c >> index 9520154..405d0ce 100644 >> --- a/drivers/infiniband/core/ucma.c >> +++ b/drivers/infiniband/core/ucma.c >> @@ -1584,8 +1584,11 @@ static ssize_t ucma_write(struct file *filp, const >> char __user *buf, >> struct rdma_ucm_cmd_hdr hdr; >> ssize_t ret; >> >> - if (WARN_ON_ONCE(!ib_safe_file_access(filp))) >> + if (!ib_safe_file_access(filp)) { >> + printk_once("ucma_write: process %d (%s) tried to do something >> hinky\n", >> + task_tgid_vnr(current), current->comm); >> return -EACCES; >> + } >> >> if (len < sizeof(hdr)) >> return -EINVAL; > > FWIW, WARN_ON_ONCE came with commit e6bd18f57aad ("IB/security: Restrict > use of the write() interface"). Would it make sense to change the other > places as well?
I guess so. Can I ask somebody of infiniband maintainers to take care of this? I just hit the warning in my automated testing environment when a thread executed key_add in between open and write, then spent some time debugging to figure out that this is an "invalid user input" rather than a kernel bug.
