On 09/20/2017 10:39 AM, Burakov, Anatoly wrote:
On 20-Sep-17 3:34 PM, Patrick MacArthur wrote:
On 09/20/2017 05:59 AM, Kuba Kozak wrote:
Add file descriptor value check before calling close() function.
Coverity issue: 141297
Fixes: 811b6b25060f ("vfio: fix file descriptor leak in multi-process")
Cc: patr...@patrickmacarthur.net
Cc: sta...@dpdk.org
Signed-off-by: Kuba Kozak <kubax.ko...@intel.com>
---
lib/librte_eal/linuxapp/eal/eal_vfio_mp_sync.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/lib/librte_eal/linuxapp/eal/eal_vfio_mp_sync.c
b/lib/librte_eal/linuxapp/eal/eal_vfio_mp_sync.c
index 7e8095c..c04f548 100644
--- a/lib/librte_eal/linuxapp/eal/eal_vfio_mp_sync.c
+++ b/lib/librte_eal/linuxapp/eal/eal_vfio_mp_sync.c
@@ -301,7 +301,8 @@ vfio_mp_sync_thread(void __rte_unused * arg)
vfio_mp_sync_send_request(conn_sock, SOCKET_ERR);
else
vfio_mp_sync_send_fd(conn_sock, fd);
- close(fd);
+ if (fd != -1)
+ close(fd);
IMHO this should be:
if (fd >= 0)
What specifically is Coverity complaining about here? Is there a
specific code path that leads to fd being -1 here?
Hi Patrick,
There's no way the fd will be 0 - the function we get the value from
returns a valid fd, or a -1 in case of error. In this particular case,
the "specific code path that leads to fd being -1" is when we can't get
a container fd for some reason. I believe this is a very remote
possibility as by the time we're spinning up the socket listening thread
we're pretty sure we have a working VFIO container, but this is a valid
fix nevertheless. Maybe having it >= 0 (or > 0, to be precise) would be
cleaner, but it really makes no difference here.
The point of my suggestion is that it would catch *any* negative value
for fd as opposed to just -1.
I agree 0 should never happen since it is stdin but it is technically a
valid fd that could occur if the user program did close(STDIN_FILENO)
for some reason.
I don't feel too strongly about it but feel like if we are going to fix
what amounts to close() possibly returning EBADF we might as well fix it
for all cases.
Thanks,
Patrick
