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authorLonglong Xia <xialonglong@kylinos.cn>2024-09-26 16:02:13 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-10-11 09:28:17 +0300
commit9462f4ca56e7d2430fdb6dcc8498244acbfc4489 (patch)
tree29bda092ec2d7002cb83aae8032b53e1ad2ee938
parentf956052e00de211b5c9ebaa1958366c23f82ee9e (diff)
downloadlinux-9462f4ca56e7d2430fdb6dcc8498244acbfc4489.tar.xz
tty: n_gsm: Fix use-after-free in gsm_cleanup_mux
BUG: KASAN: slab-use-after-free in gsm_cleanup_mux+0x77b/0x7b0 drivers/tty/n_gsm.c:3160 [n_gsm] Read of size 8 at addr ffff88815fe99c00 by task poc/3379 CPU: 0 UID: 0 PID: 3379 Comm: poc Not tainted 6.11.0+ #56 Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 Call Trace: <TASK> gsm_cleanup_mux+0x77b/0x7b0 drivers/tty/n_gsm.c:3160 [n_gsm] __pfx_gsm_cleanup_mux+0x10/0x10 drivers/tty/n_gsm.c:3124 [n_gsm] __pfx_sched_clock_cpu+0x10/0x10 kernel/sched/clock.c:389 update_load_avg+0x1c1/0x27b0 kernel/sched/fair.c:4500 __pfx_min_vruntime_cb_rotate+0x10/0x10 kernel/sched/fair.c:846 __rb_insert_augmented+0x492/0xbf0 lib/rbtree.c:161 gsmld_ioctl+0x395/0x1450 drivers/tty/n_gsm.c:3408 [n_gsm] _raw_spin_lock_irqsave+0x92/0xf0 arch/x86/include/asm/atomic.h:107 __pfx_gsmld_ioctl+0x10/0x10 drivers/tty/n_gsm.c:3822 [n_gsm] ktime_get+0x5e/0x140 kernel/time/timekeeping.c:195 ldsem_down_read+0x94/0x4e0 arch/x86/include/asm/atomic64_64.h:79 __pfx_ldsem_down_read+0x10/0x10 drivers/tty/tty_ldsem.c:338 __pfx_do_vfs_ioctl+0x10/0x10 fs/ioctl.c:805 tty_ioctl+0x643/0x1100 drivers/tty/tty_io.c:2818 Allocated by task 65: gsm_data_alloc.constprop.0+0x27/0x190 drivers/tty/n_gsm.c:926 [n_gsm] gsm_send+0x2c/0x580 drivers/tty/n_gsm.c:819 [n_gsm] gsm1_receive+0x547/0xad0 drivers/tty/n_gsm.c:3038 [n_gsm] gsmld_receive_buf+0x176/0x280 drivers/tty/n_gsm.c:3609 [n_gsm] tty_ldisc_receive_buf+0x101/0x1e0 drivers/tty/tty_buffer.c:391 tty_port_default_receive_buf+0x61/0xa0 drivers/tty/tty_port.c:39 flush_to_ldisc+0x1b0/0x750 drivers/tty/tty_buffer.c:445 process_scheduled_works+0x2b0/0x10d0 kernel/workqueue.c:3229 worker_thread+0x3dc/0x950 kernel/workqueue.c:3391 kthread+0x2a3/0x370 kernel/kthread.c:389 ret_from_fork+0x2d/0x70 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:257 Freed by task 3367: kfree+0x126/0x420 mm/slub.c:4580 gsm_cleanup_mux+0x36c/0x7b0 drivers/tty/n_gsm.c:3160 [n_gsm] gsmld_ioctl+0x395/0x1450 drivers/tty/n_gsm.c:3408 [n_gsm] tty_ioctl+0x643/0x1100 drivers/tty/tty_io.c:2818 [Analysis] gsm_msg on the tx_ctrl_list or tx_data_list of gsm_mux can be freed by multi threads through ioctl,which leads to the occurrence of uaf. Protect it by gsm tx lock. Signed-off-by: Longlong Xia <xialonglong@kylinos.cn> Cc: stable <stable@kernel.org> Suggested-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20240926130213.531959-1-xialonglong@kylinos.cn Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/tty/n_gsm.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 5d37a0984916..252849910588 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -3157,6 +3157,8 @@ static void gsm_cleanup_mux(struct gsm_mux *gsm, bool disc)
mutex_unlock(&gsm->mutex);
/* Now wipe the queues */
tty_ldisc_flush(gsm->tty);
+
+ guard(spinlock_irqsave)(&gsm->tx_lock);
list_for_each_entry_safe(txq, ntxq, &gsm->tx_ctrl_list, list)
kfree(txq);
INIT_LIST_HEAD(&gsm->tx_ctrl_list);