Subject: CVE-2022-48640: bonding: fix NULL deref in bond_rr_gen_slave_id

From: Greg Kroah-Hartman <[email-masked]>

Description
===========

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

bonding: fix NULL deref in bond_rr_gen_slave_id

Fix a NULL dereference of the struct bonding.rr_tx_counter member because
if a bond is initially created with an initial mode != zero (Round Robin)
the memory required for the counter is never created and when the mode is
changed there is never any attempt to verify the memory is allocated upon
switching modes.

This causes the following Oops on an aarch64 machine:
    [  334.686773] Unable to handle kernel paging request at virtual address ffff2c91ac905000
    [  334.694703] Mem abort info:
    [  334.697486]   ESR = 0x0000000096000004
    [  334.701234]   EC = 0x25: DABT (current EL), IL = 32 bits
    [  334.706536]   SET = 0, FnV = 0
    [  334.709579]   EA = 0, S1PTW = 0
    [  334.712719]   FSC = 0x04: level 0 translation fault
    [  334.717586] Data abort info:
    [  334.720454]   ISV = 0, ISS = 0x00000004
    [  334.724288]   CM = 0, WnR = 0
    [  334.727244] swapper pgtable: 4k pages, 48-bit VAs, pgdp=000008044d662000
    [  334.733944] [ffff2c91ac905000] pgd=0000000000000000, p4d=0000000000000000
    [  334.740734] Internal error: Oops: 96000004 [#1] SMP
    [  334.745602] Modules linked in: bonding tls veth rfkill sunrpc arm_spe_pmu vfat fat acpi_ipmi ipmi_ssif ixgbe igb i40e mdio ipmi_devintf ipmi_msghandler arm_cmn arm_dsu_pmu cppc_cpufreq acpi_tad fuse zram crct10dif_ce ast ghash_ce sbsa_gwdt nvme drm_vram_helper drm_ttm_helper nvme_core ttm xgene_hwmon
    [  334.772217] CPU: 7 PID: 2214 Comm: ping Not tainted 6.0.0-rc4-00133-g64ae13ed4784 #4
    [  334.779950] Hardware name: GIGABYTE R272-P31-00/MP32-AR1-00, BIOS F18v (SCP: 1.08.20211002) 12/01/2021
    [  334.789244] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
    [  334.796196] pc : bond_rr_gen_slave_id+0x40/0x124 [bonding]
    [  334.801691] lr : bond_xmit_roundrobin_slave_get+0x38/0xdc [bonding]
    [  334.807962] sp : ffff8000221733e0
    [  334.811265] x29: ffff8000221733e0 x28: ffffdbac8572d198 x27: ffff80002217357c
    [  334.818392] x26: 000000000000002a x25: ffffdbacb33ee000 x24: ffff07ff980fa000
    [  334.825519] x23: ffffdbacb2e398ba x22: ffff07ff98102000 x21: ffff07ff981029c0
    [  334.832646] x20: 0000000000000001 x19: ffff07ff981029c0 x18: 0000000000000014
    [  334.839773] x17: 0000000000000000 x16: ffffdbacb1004364 x15: 0000aaaabe2f5a62
    [  334.846899] x14: ffff07ff8e55d968 x13: ffff07ff8e55db30 x12: 0000000000000000
    [  334.854026] x11: ffffdbacb21532e8 x10: 0000000000000001 x9 : ffffdbac857178ec
    [  334.861153] x8 : ffff07ff9f6e5a28 x7 : 0000000000000000 x6 : 000000007c2b3742
    [  334.868279] x5 : ffff2c91ac905000 x4 : ffff2c91ac905000 x3 : ffff07ff9f554400
    [  334.875406] x2 : ffff2c91ac905000 x1 : 0000000000000001 x0 : ffff07ff981029c0
    [  334.882532] Call trace:
    [  334.884967]  bond_rr_gen_slave_id+0x40/0x124 [bonding]
    [  334.890109]  bond_xmit_roundrobin_slave_get+0x38/0xdc [bonding]
    [  334.896033]  __bond_start_xmit+0x128/0x3a0 [bonding]
    [  334.901001]  bond_start_xmit+0x54/0xb0 [bonding]
    [  334.905622]  dev_hard_start_xmit+0xb4/0x220
    [  334.909798]  __dev_queue_xmit+0x1a0/0x720
    [  334.913799]  arp_xmit+0x3c/0xbc
    [  334.916932]  arp_send_dst+0x98/0xd0
    [  334.920410]  arp_solicit+0xe8/0x230
    [  334.923888]  neigh_probe+0x60/0xb0
    [  334.927279]  __neigh_event_send+0x3b0/0x470
    [  334.931453]  neigh_resolve_output+0x70/0x90
    [  334.935626]  ip_finish_output2+0x158/0x514
    [  334.939714]  __ip_finish_output+0xac/0x1a4
    [  334.943800]  ip_finish_output+0x40/0xfc
    [  334.947626]  ip_output+0xf8/0x1a4
    [  334.950931]  ip_send_skb+0x5c/0x100
    [  334.954410]  ip_push_pending_frames+0x3c/0x60
    [  334.958758]  raw_sendmsg+0x458/0x6d0
    [  334.962325]  inet_sendmsg+0x50/0x80
    [  334.965805]  sock_sendmsg+0x60/0x6c
    [  334.969286]  __sys_sendto+0xc8/0x134
    [  334.972853]  __arm64_sys_sendto+0x34/0x4c
    [  334.976854]  invoke_syscall+0x78/0x100
    [  334.980594]  el0_svc_common.constprop.0+0x4c/0xf4
    [  334.985287]  do_el0_svc+0x38/0x4c
    [  334.988591]  el0_svc+0x34/0x10c
    [  334.991724]  el0t_64_sync_handler+0x11c/0x150
    [  334.996072]  el0t_64_sync+0x190/0x194
    [  334.999726] Code: b9001062 f9403c02 d53cd044 8b040042 (b8210040)
    [  335.005810] ---[ end trace 0000000000000000 ]---
    [  335.010416] Kernel panic - not syncing: Oops: Fatal exception in interrupt
    [  335.017279] SMP: stopping secondary CPUs
    [  335.021374] Kernel Offset: 0x5baca8eb0000 from 0xffff800008000000
    [  335.027456] PHYS_OFFSET: 0x80000000
    [  335.030932] CPU features: 0x0000,0085c029,19805c82
    [  335.035713] Memory Limit: none
    [  335.038756] Rebooting in 180 seconds..

The fix is to allocate the memory in bond_open() which is guaranteed
to be called before any packets are processed.

The Linux kernel CVE team has assigned CVE-2022-48640 to this issue.

Affected and fixed versions
===========================

	Issue introduced in 5.14 with commit 848ca9182a7d and fixed in 5.15.71 with commit ec3a6f4ffe55
	Issue introduced in 5.14 with commit 848ca9182a7d and fixed in 5.19.12 with commit 2c8e8ab53acf
	Issue introduced in 5.14 with commit 848ca9182a7d and fixed in 6.0 with commit 0e400d602f46

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2022-48640
will be updated if fixes are backported, please check that for the most
up to date information about this issue.

Affected files
==============

The file(s) affected by this issue are:
	drivers/net/bonding/bond_main.c

Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/ec3a6f4ffe556a28f6f5028bf7c4412557e7051b
	https://git.kernel.org/stable/c/2c8e8ab53acfc78da0b4a65f30cb5d306e7d78f7
	https://git.kernel.org/stable/c/0e400d602f46360752e4b32ce842dba3808e15e6