diff mbox series

[v3] sfc: potential dereference null pointer of rx_queue->page_ring

Message ID 20211220021753.723161-1-jiasheng@iscas.ac.cn (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series [v3] sfc: potential dereference null pointer of rx_queue->page_ring | expand

Checks

Context Check Description
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix warning Target tree name not specified in the subject
netdev/cover_letter success Single patches do not need cover letters
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1 this patch: 1
netdev/cc_maintainers fail 1 blamed authors not CCed: amaftei@solarflare.com; 1 maintainers not CCed: amaftei@solarflare.com
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 1 this patch: 1
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 19 lines checked
netdev/kdoc success Errors and warnings before: 57 this patch: 57
netdev/source_inline success Was 0 now: 0
netdev/tree_selection success Guessing tree name failed - patch did not apply

Commit Message

Jiasheng Jiang Dec. 20, 2021, 2:17 a.m. UTC
The return value of kcalloc() needs to be checked.
To avoid dereference of null pointer in case of the failure of alloc,
such as efx_fini_rx_recycle_ring().
Therefore, it should be better to change the definition of page_ptr_mask
to signed int and then assign the page_ptr_mask to -1 when page_ring is
NULL, in order to avoid the use in the loop.

Fixes: 3d95b884392f ("sfc: move more rx code")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
---
Changelog:

v2 -> v3

*Change 1. Casade return -ENOMEM when alloc fails and deal with the
error.
*Change 2. Set size to -1 instead of return error.
---
 drivers/net/ethernet/sfc/net_driver.h | 2 +-
 drivers/net/ethernet/sfc/rx_common.c  | 5 ++++-
 2 files changed, 5 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
index 9b4b25704271..beba3e0a6027 100644
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -407,7 +407,7 @@  struct efx_rx_queue {
 	unsigned int page_recycle_count;
 	unsigned int page_recycle_failed;
 	unsigned int page_recycle_full;
-	unsigned int page_ptr_mask;
+	int page_ptr_mask;
 	unsigned int max_fill;
 	unsigned int fast_fill_trigger;
 	unsigned int min_fill;
diff --git a/drivers/net/ethernet/sfc/rx_common.c b/drivers/net/ethernet/sfc/rx_common.c
index 68fc7d317693..d9d0a5805f1c 100644
--- a/drivers/net/ethernet/sfc/rx_common.c
+++ b/drivers/net/ethernet/sfc/rx_common.c
@@ -150,7 +150,10 @@  static void efx_init_rx_recycle_ring(struct efx_rx_queue *rx_queue)
 					    efx->rx_bufs_per_page);
 	rx_queue->page_ring = kcalloc(page_ring_size,
 				      sizeof(*rx_queue->page_ring), GFP_KERNEL);
-	rx_queue->page_ptr_mask = page_ring_size - 1;
+	if (!rx_queue->page_ring)
+		rx_queue->page_ptr_mask = -1;
+	else
+		rx_queue->page_ptr_mask = page_ring_size - 1;
 }
 
 static void efx_fini_rx_recycle_ring(struct efx_rx_queue *rx_queue)