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[1/2,net,V2] net: vertexcom: mse102x: Fix possible double free of TX skb

Message ID 20241105163101.33216-1-wahrenst@gmx.net (mailing list archive)
State New
Delegated to: Netdev Maintainers
Headers show
Series [1/2,net,V2] net: vertexcom: mse102x: Fix possible double free of TX skb | expand

Checks

Context Check Description
netdev/series_format success Single patches do not need cover letters
netdev/tree_selection success Clearly marked for net
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 3 this patch: 3
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 1 maintainers not CCed: horms@kernel.org
netdev/build_clang success Errors and warnings before: 3 this patch: 3
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 4 this patch: 4
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 23 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest fail net-next-2024-11-05--18-00 (tests: 782)

Commit Message

Stefan Wahren Nov. 5, 2024, 4:31 p.m. UTC
The scope of the TX skb is wider than just mse102x_tx_frame_spi(),
so in case the TX skb room needs to be expanded, we should free the
the temporary skb instead of the original skb. Otherwise the original
TX skb pointer would be freed again in mse102x_tx_work(), which leads
to crashes:

  Internal error: Oops: 0000000096000004 [#2] PREEMPT SMP
  CPU: 0 PID: 712 Comm: kworker/0:1 Tainted: G      D            6.6.23
  Hardware name: chargebyte Charge SOM DC-ONE (DT)
  Workqueue: events mse102x_tx_work [mse102x]
  pstate: 20400009 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
  pc : skb_release_data+0xb8/0x1d8
  lr : skb_release_data+0x1ac/0x1d8
  sp : ffff8000819a3cc0
  x29: ffff8000819a3cc0 x28: ffff0000046daa60 x27: ffff0000057f2dc0
  x26: ffff000005386c00 x25: 0000000000000002 x24: 00000000ffffffff
  x23: 0000000000000000 x22: 0000000000000001 x21: ffff0000057f2e50
  x20: 0000000000000006 x19: 0000000000000000 x18: ffff00003fdacfcc
  x17: e69ad452d0c49def x16: 84a005feff870102 x15: 0000000000000000
  x14: 000000000000024a x13: 0000000000000002 x12: 0000000000000000
  x11: 0000000000000400 x10: 0000000000000930 x9 : ffff00003fd913e8
  x8 : fffffc00001bc008
  x7 : 0000000000000000 x6 : 0000000000000008
  x5 : ffff00003fd91340 x4 : 0000000000000000 x3 : 0000000000000009
  x2 : 00000000fffffffe x1 : 0000000000000000 x0 : 0000000000000000
  Call trace:
   skb_release_data+0xb8/0x1d8
   kfree_skb_reason+0x48/0xb0
   mse102x_tx_work+0x164/0x35c [mse102x]
   process_one_work+0x138/0x260
   worker_thread+0x32c/0x438
   kthread+0x118/0x11c
   ret_from_fork+0x10/0x20
  Code: aa1303e0 97fffab6 72001c1f 54000141 (f9400660)

Cc: stable@vger.kernel.org
Fixes: 2f207cbf0dd4 ("net: vertexcom: Add MSE102x SPI support")
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
---
 drivers/net/ethernet/vertexcom/mse102x.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--
2.34.1
diff mbox series

Patch

diff --git a/drivers/net/ethernet/vertexcom/mse102x.c b/drivers/net/ethernet/vertexcom/mse102x.c
index a04d4073def9..2c37957478fb 100644
--- a/drivers/net/ethernet/vertexcom/mse102x.c
+++ b/drivers/net/ethernet/vertexcom/mse102x.c
@@ -222,7 +222,7 @@  static int mse102x_tx_frame_spi(struct mse102x_net *mse, struct sk_buff *txp,
 	struct mse102x_net_spi *mses = to_mse102x_spi(mse);
 	struct spi_transfer *xfer = &mses->spi_xfer;
 	struct spi_message *msg = &mses->spi_msg;
-	struct sk_buff *tskb;
+	struct sk_buff *tskb = NULL;
 	int ret;

 	netif_dbg(mse, tx_queued, mse->ndev, "%s: skb %p, %d@%p\n",
@@ -235,7 +235,6 @@  static int mse102x_tx_frame_spi(struct mse102x_net *mse, struct sk_buff *txp,
 		if (!tskb)
 			return -ENOMEM;

-		dev_kfree_skb(txp);
 		txp = tskb;
 	}

@@ -257,6 +256,8 @@  static int mse102x_tx_frame_spi(struct mse102x_net *mse, struct sk_buff *txp,
 		mse->stats.xfer_err++;
 	}

+	dev_kfree_skb(tskb);
+
 	return ret;
 }