[fips-8.6] can: bcm: Fix UAF in bcm_proc_show()

[bmastbergen]

jira VULN-36334
cve CVE-2023-52922

commit-author YueHaibing <[email protected]>
commit 55c3b96074f3f9b0aee19bf93cd71af7516582bb

BUG: KASAN: slab-use-after-free in bcm_proc_show+0x969/0xa80 Read of size 8 at addr ffff888155846230 by task cat/7862

CPU: 1 PID: 7862 Comm: cat Not tainted 6.5.0-rc1-00153-gc8746099c197 #230 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace:
 <TASK>
 dump_stack_lvl+0xd5/0x150
 print_report+0xc1/0x5e0
 kasan_report+0xba/0xf0
 bcm_proc_show+0x969/0xa80
 seq_read_iter+0x4f6/0x1260
 seq_read+0x165/0x210
 proc_reg_read+0x227/0x300
 vfs_read+0x1d5/0x8d0
 ksys_read+0x11e/0x240
 do_syscall_64+0x35/0xb0
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Allocated by task 7846:
 kasan_save_stack+0x1e/0x40
 kasan_set_track+0x21/0x30
 __kasan_kmalloc+0x9e/0xa0
 bcm_sendmsg+0x264b/0x44e0
 sock_sendmsg+0xda/0x180
 ____sys_sendmsg+0x735/0x920
 ___sys_sendmsg+0x11d/0x1b0
 __sys_sendmsg+0xfa/0x1d0
 do_syscall_64+0x35/0xb0
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Freed by task 7846:
 kasan_save_stack+0x1e/0x40
 kasan_set_track+0x21/0x30
 kasan_save_free_info+0x27/0x40
 ____kasan_slab_free+0x161/0x1c0
 slab_free_freelist_hook+0x119/0x220
 __kmem_cache_free+0xb4/0x2e0
 rcu_core+0x809/0x1bd0

bcm_op is freed before procfs entry be removed in bcm_release(), this lead to bcm_proc_show() may read the freed bcm_op.

Fixes: ffd980f976e7 ("[CAN]: Add broadcast manager (bcm) protocol")
	Signed-off-by: YueHaibing <[email protected]>
	Reviewed-by: Oliver Hartkopp <[email protected]>
	Acked-by: Oliver Hartkopp <[email protected]>
Link: https://lore.kernel.org/all/[email protected]
	Cc: [email protected]
	Signed-off-by: Marc Kleine-Budde <[email protected]>
(cherry picked from commit 55c3b96074f3f9b0aee19bf93cd71af7516582bb)
	Signed-off-by: Brett Mastbergen <[email protected]>

Build Log

/home/brett/kernel-src-tree
Running make mrproper...
[TIMER]{MRPROPER}: 12s
x86_64 architecture detected, copying config
'configs/kernel-x86_64.config' -> '.config'
Setting Local Version for build
CONFIG_LOCALVERSION="-b_f-8-c_4.18.0-553.16.1_VULN-36334-59f2fd1e399f"
Making olddefconfig
--
  HOSTLD  scripts/kconfig/conf
scripts/kconfig/conf  --olddefconfig Kconfig
#
# configuration written to .config
#
Starting Build
scripts/kconfig/conf  --syncconfig Kconfig
  SYSTBL  arch/x86/include/generated/asm/syscalls_32.h
  SYSHDR  arch/x86/include/generated/asm/unistd_32_ia32.h
  SYSTBL  arch/x86/include/generated/asm/syscalls_64.h
  HYPERCALLS arch/x86/include/generated/asm/xen-hypercalls.h
--
  LD [M]  sound/virtio/virtio_snd.ko
  LD [M]  sound/usb/usx2y/snd-usb-usx2y.ko
  LD [M]  sound/x86/snd-hdmi-lpe-audio.ko
  LD [M]  sound/xen/snd_xen_front.ko
  LD [M]  virt/lib/irqbypass.ko
[TIMER]{BUILD}: 1086s
Making Modules
  INSTALL arch/x86/crypto/camellia-aesni-avx-x86_64.ko
  INSTALL arch/x86/crypto/camellia-aesni-avx2.ko
  INSTALL arch/x86/crypto/blowfish-x86_64.ko
  INSTALL arch/x86/crypto/camellia-x86_64.ko
--
  INSTALL sound/usb/usx2y/snd-usb-usx2y.ko
  INSTALL sound/x86/snd-hdmi-lpe-audio.ko
  INSTALL virt/lib/irqbypass.ko
  INSTALL sound/xen/snd_xen_front.ko
  DEPMOD  4.18.0-b_f-8-c_4.18.0-553.16.1_VULN-36334-59f2fd1e399f+
[TIMER]{MODULES}: 18s
Making Install
sh ./arch/x86/boot/install.sh 4.18.0-b_f-8-c_4.18.0-553.16.1_VULN-36334-59f2fd1e399f+ arch/x86/boot/bzImage \
	System.map "/boot"
[TIMER]{INSTALL}: 109s
Checking kABI
kABI check passed
Setting Default Kernel to /boot/vmlinuz-4.18.0-b_f-8-c_4.18.0-553.16.1_VULN-36334-59f2fd1e399f+ and Index to 2
Hopefully Grub2.0 took everything ... rebooting after time metrices
[TIMER]{MRPROPER}: 12s
[TIMER]{BUILD}: 1086s
[TIMER]{MODULES}: 18s
[TIMER]{INSTALL}: 109s
[TIMER]{TOTAL} 1241s
Rebooting in 10 seconds

Testing

selftest-4.18.0-553.16.1.el8_6.ciqfips.0.8.1.x86_64.log

selftest-4.18.0-b_f-8-c_4.18.0-553.16.1_VULN-36334-59f2fd1e399f+.log

brett@lycia ~/ciq/vuln-36334 % grep ^ok selftest-4.18.0-553.16.1.el8_6.ciqfips.0.8.1.x86_64.log | wc -l
296
brett@lycia ~/ciq/vuln-36334 % grep ^ok selftest-4.18.0-b_f-8-c_4.18.0-553.16.1_VULN-36334-59f2fd1e399f+.log | wc -l
298
brett@lycia ~/ciq/vuln-36334 %

[thefossguy-ciq]

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