diff options
author | Coly Li <colyli@suse.de> | 2020-10-02 16:27:28 +0800 |
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committer | David S. Miller <davem@davemloft.net> | 2020-10-02 15:27:08 -0700 |
commit | c381b07941adc2274ce552daf86c94701c5e265a (patch) | |
tree | e2180c3d816a8848b4ea122142ee80236e07bacf /sound/drivers/vx/vx_hwdep.c | |
parent | f30e25a9d1b25ac8d40071c4dc2679ad0fcdc55a (diff) |
net: introduce helper sendpage_ok() in include/linux/net.h
The original problem was from nvme-over-tcp code, who mistakenly uses
kernel_sendpage() to send pages allocated by __get_free_pages() without
__GFP_COMP flag. Such pages don't have refcount (page_count is 0) on
tail pages, sending them by kernel_sendpage() may trigger a kernel panic
from a corrupted kernel heap, because these pages are incorrectly freed
in network stack as page_count 0 pages.
This patch introduces a helper sendpage_ok(), it returns true if the
checking page,
- is not slab page: PageSlab(page) is false.
- has page refcount: page_count(page) is not zero
All drivers who want to send page to remote end by kernel_sendpage()
may use this helper to check whether the page is OK. If the helper does
not return true, the driver should try other non sendpage method (e.g.
sock_no_sendpage()) to handle the page.
Signed-off-by: Coly Li <colyli@suse.de>
Cc: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Jan Kara <jack@suse.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Mikhail Skorzhinskii <mskorzhinskiy@solarflare.com>
Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Vlastimil Babka <vbabka@suse.com>
Cc: stable@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'sound/drivers/vx/vx_hwdep.c')
0 files changed, 0 insertions, 0 deletions