On Thu, May 07, 2020 at 10:10:12AM +0300, Leon Romanovsky wrote:
> From: Jack Morgenstein <jackm@xxxxxxxxxxxxxxxxxx>
>
> The IB core pkey cache is populated by procedure ib_cache_update().
> Initially, the pkey cache pointer is NULL. ib_cache_update allocates
> a buffer and populates it with the device's pkeys, via repeated calls
> to procedure ib_query_pkey().
>
> If there is a failure in populating the pkey buffer via ib_query_pkey(),
> ib_cache_update does not replace the old pkey buffer cache with the
> updated one -- it leaves the old cache as is.
>
> Since initially the pkey buffer cache is NULL, when calling
> ib_cache_update the first time, a failure in ib_query_pkey() will cause
> the pkey buffer cache pointer to remain NULL.
>
> In this situation, any calls subsequent to ib_get_cached_pkey(),
> ib_find_cached_pkey(), or ib_find_cached_pkey_exact() will try to
> dereference the NULL pkey cache pointer, causing a kernel panic.
>
> Fix this by checking the ib_cache_update() return value.
>
> Fixes: 8faea9fd4a39 ("RDMA/cache: Move the cache per-port data into the main ib_port_data")
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Signed-off-by: Jack Morgenstein <jackm@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxxxx>
> ---
> Changelog:
> v2: Removed error unwinding
> v1: https://lore.kernel.org/linux-rdma/20200506053213.566264-1-leon@xxxxxxxxxx
> I rewrote the patch to take care of ib_cache_update() return value.
> v0: https://lore.kernel.org/linux-rdma/20200426075811.129814-1-leon@xxxxxxxxxx
> ---
> drivers/infiniband/core/cache.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
Applied to for-rc
Thanks,
Jason
