CVE-2023-52784 — bonding: stop the device in bond_setup_by_slave()

Affected: Linux

In the Linux kernel, the following vulnerability has been resolved:

bonding: stop the device in bond_setup_by_slave()

Commit 9eed321cde22 ("net: lapbether: only support ethernet devices") has been able to keep syzbot away from net/lapb, until today.

In the following splat [1], the issue is that a lapbether device has been created on a bonding device without members. Then adding a non ARPHRD_ETHER member forced the bonding master to change its type.

The fix is to make sure we call dev_close() in bond_setup_by_slave() so that the potential linked lapbether devices (or any other devices having assumptions on the physical device) are removed.

A similar bug has been addressed in commit 40baec225765 ("bonding: fix panic on non-ARPHRD_ETHER enslave failure")

[1] skbuff: skb_under_panic: text:ffff800089508810 len:44 put:40 head:ffff0000c78e7c00 data:ffff0000c78e7bea tail:0x16 end:0x140 dev:bond0 kernel BUG at net/core/skbuff.c:192 ! Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 6007 Comm: syz-executor383 Not tainted 6.6.0-rc3-syzkaller-gbf6547d8715b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023 pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : skb_panic net/core/skbuff.c:188 [inline] pc : skb_under_panic+0x13c/0x140 net/core/skbuff.c:202 lr : skb_panic net/core/skbuff.c:188 [inline] lr : skb_under_panic+0x13c/0x140 net/core/skbuff.c:202 sp : ffff800096a06aa0 x29: ff…

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CVE-2023-52784 — bonding: stop the device in bond_setup_by_slave()