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authorSouptick Joarder <jrdr.linux@gmail.com>2020-10-15 20:13:15 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-10-16 11:11:22 -0700
commitfa63f083b3492b5ed5332b8d7c90b03b5ef24a1d (patch)
tree2200347fd904d625329ee7f170b670cdf6393293
parent64ead5201e757159d1d83a5e0752090c2ab3319f (diff)
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] Fixes: e8de370188d09 ("rapidio: add mport char device driver") Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: 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> Link: https://lkml.kernel.org/r/1600227737-20785-1-git-send-email-jrdr.linux@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/rapidio/devices/rio_mport_cdev.c13
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;
}