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author | Souptick Joarder <jrdr.linux@gmail.com> | 2020-09-17 11:56:44 +1000 |
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committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2020-09-17 11:56:44 +1000 |
commit | 4b838d5fa4b3d2be38e4c288b652d44a85d8f87a (patch) | |
tree | dc756dee15b57ddf8fda299b30b46b80a6d10028 | |
parent | 2c8fdaf32752727e6db897a1c74bdd03709288a9 (diff) | |
download | linux-4b838d5fa4b3d2be38e4c288b652d44a85d8f87a.tar.gz linux-4b838d5fa4b3d2be38e4c288b652d44a85d8f87a.tar.xz |
rapidio: fix error handling path
rio_dma_transfer() attempts to clamp the return value of
pin_user_pages_fast() to be >= 0. However, the attempt fails because
nr_pages is overridden a few lines later, and restored to the undesirable
-ERRNO value.
The return value is ultimately stored in nr_pages, which in turn is passed
to unpin_user_pages(), which expects nr_pages >= 0, else, disaster.
Fix this by fixing the nesting of the assignment to nr_pages: nr_pages
should be clamped to zero if pin_user_pages_fast() returns -ERRNO, or set
to the return value of pin_user_pages_fast(), otherwise.
[jhubbard@nvidia.com: new changelog]
Link: https://lkml.kernel.org/r/1600227737-20785-1-git-send-email-jrdr.linux@gmail.com
Fixes: e8de370188d09 ("rapidio: add mport char device driver")
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Alexandre Bounine <alex.bou9@gmail.com>
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Cc: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
-rw-r--r-- | drivers/rapidio/devices/rio_mport_cdev.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/drivers/rapidio/devices/rio_mport_cdev.c b/drivers/rapidio/devices/rio_mport_cdev.c index a30342942e26..163b6c72501d 100644 --- a/drivers/rapidio/devices/rio_mport_cdev.c +++ b/drivers/rapidio/devices/rio_mport_cdev.c @@ -871,15 +871,16 @@ rio_dma_transfer(struct file *filp, u32 transfer_mode, rmcd_error("pin_user_pages_fast err=%ld", pinned); nr_pages = 0; - } else + } else { rmcd_error("pinned %ld out of %ld pages", pinned, nr_pages); + /* + * Set nr_pages up to mean "how many pages to unpin, in + * the error handler: + */ + nr_pages = pinned; + } ret = -EFAULT; - /* - * Set nr_pages up to mean "how many pages to unpin, in - * the error handler: - */ - nr_pages = pinned; goto err_pg; } |