6.6-stable patches

added patches:
	net-bonding-fix-use-after-free-in-bond_xmit_broadcast.patch

diff --git a/queue-6.6/net-bonding-fix-use-after-free-in-bond_xmit_broadcast.patch b/queue-6.6/net-bonding-fix-use-after-free-in-bond_xmit_broadcast.patch
new file mode 100644 (file)
index 0000000..faed909
--- /dev/null
+++ b/queue-6.6/net-bonding-fix-use-after-free-in-bond_xmit_broadcast.patch
@@ -0,0 +1,89 @@
+From 2884bf72fb8f03409e423397319205de48adca16 Mon Sep 17 00:00:00 2001
+From: Xiang Mei <xmei5@asu.edu>
+Date: Thu, 26 Mar 2026 00:55:53 -0700
+Subject: net: bonding: fix use-after-free in bond_xmit_broadcast()
+
+From: Xiang Mei <xmei5@asu.edu>
+
+commit 2884bf72fb8f03409e423397319205de48adca16 upstream.
+
+bond_xmit_broadcast() reuses the original skb for the last slave
+(determined by bond_is_last_slave()) and clones it for others.
+Concurrent slave enslave/release can mutate the slave list during
+RCU-protected iteration, changing which slave is "last" mid-loop.
+This causes the original skb to be double-consumed (double-freed).
+
+Replace the racy bond_is_last_slave() check with a simple index
+comparison (i + 1 == slaves_count) against the pre-snapshot slave
+count taken via READ_ONCE() before the loop.  This preserves the
+zero-copy optimization for the last slave while making the "last"
+determination stable against concurrent list mutations.
+
+The UAF can trigger the following crash:
+
+==================================================================
+BUG: KASAN: slab-use-after-free in skb_clone
+Read of size 8 at addr ffff888100ef8d40 by task exploit/147
+
+CPU: 1 UID: 0 PID: 147 Comm: exploit Not tainted 7.0.0-rc3+ #4 PREEMPTLAZY
+Call Trace:
+ <TASK>
+ dump_stack_lvl (lib/dump_stack.c:123)
+ print_report (mm/kasan/report.c:379 mm/kasan/report.c:482)
+ kasan_report (mm/kasan/report.c:597)
+ skb_clone (include/linux/skbuff.h:1724 include/linux/skbuff.h:1792 include/linux/skbuff.h:3396 net/core/skbuff.c:2108)
+ bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5334)
+ bond_start_xmit (drivers/net/bonding/bond_main.c:5567 drivers/net/bonding/bond_main.c:5593)
+ dev_hard_start_xmit (include/linux/netdevice.h:5325 include/linux/netdevice.h:5334 net/core/dev.c:3871 net/core/dev.c:3887)
+ __dev_queue_xmit (include/linux/netdevice.h:3601 net/core/dev.c:4838)
+ ip6_finish_output2 (include/net/neighbour.h:540 include/net/neighbour.h:554 net/ipv6/ip6_output.c:136)
+ ip6_finish_output (net/ipv6/ip6_output.c:208 net/ipv6/ip6_output.c:219)
+ ip6_output (net/ipv6/ip6_output.c:250)
+ ip6_send_skb (net/ipv6/ip6_output.c:1985)
+ udp_v6_send_skb (net/ipv6/udp.c:1442)
+ udpv6_sendmsg (net/ipv6/udp.c:1733)
+ __sys_sendto (net/socket.c:730 net/socket.c:742 net/socket.c:2206)
+ __x64_sys_sendto (net/socket.c:2209)
+ do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
+ entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
+ </TASK>
+
+Allocated by task 147:
+
+Freed by task 147:
+
+The buggy address belongs to the object at ffff888100ef8c80
+ which belongs to the cache skbuff_head_cache of size 224
+The buggy address is located 192 bytes inside of
+ freed 224-byte region [ffff888100ef8c80, ffff888100ef8d60)
+
+Memory state around the buggy address:
+ ffff888100ef8c00: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
+ ffff888100ef8c80: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
+>ffff888100ef8d00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
+                                                    ^
+ ffff888100ef8d80: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
+ ffff888100ef8e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
+==================================================================
+
+Fixes: 4e5bd03ae346 ("net: bonding: fix bond_xmit_broadcast return value error bug")
+Reported-by: Weiming Shi <bestswngs@gmail.com>
+Signed-off-by: Xiang Mei <xmei5@asu.edu>
+Link: https://patch.msgid.link/20260326075553.3960562-1-xmei5@asu.edu
+Signed-off-by: Paolo Abeni <pabeni@redhat.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/net/bonding/bond_main.c |    2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/drivers/net/bonding/bond_main.c
++++ b/drivers/net/bonding/bond_main.c
+@@ -5349,7 +5349,7 @@ static netdev_tx_t bond_xmit_broadcast(s
+               if (!(bond_slave_is_up(slave) && slave->link == BOND_LINK_UP))
+                       continue;
+ 
+-              if (bond_is_last_slave(bond, slave)) {
++              if (i + 1 == slaves_count) {
+                       skb2 = skb;
+                       skb_used = true;
+               } else {

diff --git a/queue-6.6/series b/queue-6.6/series
index 906a64334509f36d3edf0ed5b205c2fe1822b277..8988e9410f42f5698a987d249d38623a6b0a783f 100644 (file)
--- a/queue-6.6/series
+++ b/queue-6.6/series
@@ -435,3 +435,4 @@ rdma-during-rereg_mr-ensure-that-rereg_access-is-compatible.patch
 rdma-umem-fix-kernel-doc-warnings.patch
 rdma-move-dma-block-iterator-logic-into-dedicated-files.patch
 rdma-umem-fix-truncation-for-block-sizes-4g.patch
+net-bonding-fix-use-after-free-in-bond_xmit_broadcast.patch