linux-stable.git/net/nfc, branch v5.4.232 Linux kernel stable tree net: nfc: Fix use-after-free in local_cleanup() 2023-02-06T06:52:37+00:00 Jisoo Jang jisoo.jang@yonsei.ac.kr 2023-01-11T13:19:14+00:00 a59cdbda3714e11aa3ab579132864c4c8c6d54f9 [ Upstream commit 4bb4db7f3187c6e3de6b229ffc87cdb30a2d22b6 ] Fix a use-after-free that occurs in kfree_skb() called from local_cleanup(). This could happen when killing nfc daemon (e.g. neard) after detaching an nfc device. When detaching an nfc device, local_cleanup() called from nfc_llcp_unregister_device() frees local->rx_pending and decreases local->ref by kref_put() in nfc_llcp_local_put(). In the terminating process, nfc daemon releases all sockets and it leads to decreasing local->ref. After the last release of local->ref, local_cleanup() called from local_release() frees local->rx_pending again, which leads to the bug. Setting local->rx_pending to NULL in local_cleanup() could prevent use-after-free when local_cleanup() is called twice. Found by a modified version of syzkaller. BUG: KASAN: use-after-free in kfree_skb() Call Trace: dump_stack_lvl (lib/dump_stack.c:106) print_address_description.constprop.0.cold (mm/kasan/report.c:306) kasan_check_range (mm/kasan/generic.c:189) kfree_skb (net/core/skbuff.c:955) local_cleanup (net/nfc/llcp_core.c:159) nfc_llcp_local_put.part.0 (net/nfc/llcp_core.c:172) nfc_llcp_local_put (net/nfc/llcp_core.c:181) llcp_sock_destruct (net/nfc/llcp_sock.c:959) __sk_destruct (net/core/sock.c:2133) sk_destruct (net/core/sock.c:2181) __sk_free (net/core/sock.c:2192) sk_free (net/core/sock.c:2203) llcp_sock_release (net/nfc/llcp_sock.c:646) __sock_release (net/socket.c:650) sock_close (net/socket.c:1365) __fput (fs/file_table.c:306) task_work_run (kernel/task_work.c:179) ptrace_notify (kernel/signal.c:2354) syscall_exit_to_user_mode_prepare (kernel/entry/common.c:278) syscall_exit_to_user_mode (kernel/entry/common.c:296) do_syscall_64 (arch/x86/entry/common.c:86) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:106) Allocated by task 4719: kasan_save_stack (mm/kasan/common.c:45) __kasan_slab_alloc (mm/kasan/common.c:325) slab_post_alloc_hook (mm/slab.h:766) kmem_cache_alloc_node (mm/slub.c:3497) __alloc_skb (net/core/skbuff.c:552) pn533_recv_response (drivers/nfc/pn533/usb.c:65) __usb_hcd_giveback_urb (drivers/usb/core/hcd.c:1671) usb_giveback_urb_bh (drivers/usb/core/hcd.c:1704) tasklet_action_common.isra.0 (kernel/softirq.c:797) __do_softirq (kernel/softirq.c:571) Freed by task 1901: kasan_save_stack (mm/kasan/common.c:45) kasan_set_track (mm/kasan/common.c:52) kasan_save_free_info (mm/kasan/genericdd.c:518) __kasan_slab_free (mm/kasan/common.c:236) kmem_cache_free (mm/slub.c:3809) kfree_skbmem (net/core/skbuff.c:874) kfree_skb (net/core/skbuff.c:931) local_cleanup (net/nfc/llcp_core.c:159) nfc_llcp_unregister_device (net/nfc/llcp_core.c:1617) nfc_unregister_device (net/nfc/core.c:1179) pn53x_unregister_nfc (drivers/nfc/pn533/pn533.c:2846) pn533_usb_disconnect (drivers/nfc/pn533/usb.c:579) usb_unbind_interface (drivers/usb/core/driver.c:458) device_release_driver_internal (drivers/base/dd.c:1279) bus_remove_device (drivers/base/bus.c:529) device_del (drivers/base/core.c:3665) usb_disable_device (drivers/usb/core/message.c:1420) usb_disconnect (drivers/usb/core.c:2261) hub_event (drivers/usb/core/hub.c:5833) process_one_work (arch/x86/include/asm/jump_label.h:27 include/linux/jump_label.h:212 include/trace/events/workqueue.h:108 kernel/workqueue.c:2281) worker_thread (include/linux/list.h:282 kernel/workqueue.c:2423) kthread (kernel/kthread.c:319) ret_from_fork (arch/x86/entry/entry_64.S:301) Fixes: 3536da06db0b ("NFC: llcp: Clean local timers and works when removing a device") Signed-off-by: Jisoo Jang <jisoo.jang@yonsei.ac.kr> Link: https://lore.kernel.org/r/20230111131914.3338838-1-jisoo.jang@yonsei.ac.kr Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 4bb4db7f3187c6e3de6b229ffc87cdb30a2d22b6 ]

Fix a use-after-free that occurs in kfree_skb() called from
local_cleanup(). This could happen when killing nfc daemon (e.g. neard)
after detaching an nfc device.
When detaching an nfc device, local_cleanup() called from
nfc_llcp_unregister_device() frees local->rx_pending and decreases
local->ref by kref_put() in nfc_llcp_local_put().
In the terminating process, nfc daemon releases all sockets and it leads
to decreasing local->ref. After the last release of local->ref,
local_cleanup() called from local_release() frees local->rx_pending
again, which leads to the bug.

Setting local->rx_pending to NULL in local_cleanup() could prevent
use-after-free when local_cleanup() is called twice.

Found by a modified version of syzkaller.

BUG: KASAN: use-after-free in kfree_skb()

Call Trace:
dump_stack_lvl (lib/dump_stack.c:106)
print_address_description.constprop.0.cold (mm/kasan/report.c:306)
kasan_check_range (mm/kasan/generic.c:189)
kfree_skb (net/core/skbuff.c:955)
local_cleanup (net/nfc/llcp_core.c:159)
nfc_llcp_local_put.part.0 (net/nfc/llcp_core.c:172)
nfc_llcp_local_put (net/nfc/llcp_core.c:181)
llcp_sock_destruct (net/nfc/llcp_sock.c:959)
__sk_destruct (net/core/sock.c:2133)
sk_destruct (net/core/sock.c:2181)
__sk_free (net/core/sock.c:2192)
sk_free (net/core/sock.c:2203)
llcp_sock_release (net/nfc/llcp_sock.c:646)
__sock_release (net/socket.c:650)
sock_close (net/socket.c:1365)
__fput (fs/file_table.c:306)
task_work_run (kernel/task_work.c:179)
ptrace_notify (kernel/signal.c:2354)
syscall_exit_to_user_mode_prepare (kernel/entry/common.c:278)
syscall_exit_to_user_mode (kernel/entry/common.c:296)
do_syscall_64 (arch/x86/entry/common.c:86)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:106)

Allocated by task 4719:
kasan_save_stack (mm/kasan/common.c:45)
__kasan_slab_alloc (mm/kasan/common.c:325)
slab_post_alloc_hook (mm/slab.h:766)
kmem_cache_alloc_node (mm/slub.c:3497)
__alloc_skb (net/core/skbuff.c:552)
pn533_recv_response (drivers/nfc/pn533/usb.c:65)
__usb_hcd_giveback_urb (drivers/usb/core/hcd.c:1671)
usb_giveback_urb_bh (drivers/usb/core/hcd.c:1704)
tasklet_action_common.isra.0 (kernel/softirq.c:797)
__do_softirq (kernel/softirq.c:571)

Freed by task 1901:
kasan_save_stack (mm/kasan/common.c:45)
kasan_set_track (mm/kasan/common.c:52)
kasan_save_free_info (mm/kasan/genericdd.c:518)
__kasan_slab_free (mm/kasan/common.c:236)
kmem_cache_free (mm/slub.c:3809)
kfree_skbmem (net/core/skbuff.c:874)
kfree_skb (net/core/skbuff.c:931)
local_cleanup (net/nfc/llcp_core.c:159)
nfc_llcp_unregister_device (net/nfc/llcp_core.c:1617)
nfc_unregister_device (net/nfc/core.c:1179)
pn53x_unregister_nfc (drivers/nfc/pn533/pn533.c:2846)
pn533_usb_disconnect (drivers/nfc/pn533/usb.c:579)
usb_unbind_interface (drivers/usb/core/driver.c:458)
device_release_driver_internal (drivers/base/dd.c:1279)
bus_remove_device (drivers/base/bus.c:529)
device_del (drivers/base/core.c:3665)
usb_disable_device (drivers/usb/core/message.c:1420)
usb_disconnect (drivers/usb/core.c:2261)
hub_event (drivers/usb/core/hub.c:5833)
process_one_work (arch/x86/include/asm/jump_label.h:27 include/linux/jump_label.h:212 include/trace/events/workqueue.h:108 kernel/workqueue.c:2281)
worker_thread (include/linux/list.h:282 kernel/workqueue.c:2423)
kthread (kernel/kthread.c:319)
ret_from_fork (arch/x86/entry/entry_64.S:301)

Fixes: 3536da06db0b ("NFC: llcp: Clean local timers and works when removing a device")
Signed-off-by: Jisoo Jang <jisoo.jang@yonsei.ac.kr>
Link: https://lore.kernel.org/r/20230111131914.3338838-1-jisoo.jang@yonsei.ac.kr
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
nfc: Fix potential resource leaks 2023-01-18T10:41:57+00:00 Miaoqian Lin linmq006@gmail.com 2022-12-23T07:37:18+00:00 d8e410315ad393b23520b5db0706be853589c548 [ Upstream commit df49908f3c52d211aea5e2a14a93bbe67a2cb3af ] nfc_get_device() take reference for the device, add missing nfc_put_device() to release it when not need anymore. Also fix the style warnning by use error EOPNOTSUPP instead of ENOTSUPP. Fixes: 5ce3f32b5264 ("NFC: netlink: SE API implementation") Fixes: 29e76924cf08 ("nfc: netlink: Add capability to reply to vendor_cmd with data") Signed-off-by: Miaoqian Lin <linmq006@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit df49908f3c52d211aea5e2a14a93bbe67a2cb3af ]

nfc_get_device() take reference for the device, add missing
nfc_put_device() to release it when not need anymore.
Also fix the style warnning by use error EOPNOTSUPP instead of
ENOTSUPP.

Fixes: 5ce3f32b5264 ("NFC: netlink: SE API implementation")
Fixes: 29e76924cf08 ("nfc: netlink: Add capability to reply to vendor_cmd with data")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
NFC: nci: Bounds check struct nfc_target arrays 2022-12-14T10:30:46+00:00 Kees Cook keescook@chromium.org 2022-12-02T21:44:14+00:00 6778434706940b8fad7ef35f410d2b9929f256d2 [ Upstream commit e329e71013c9b5a4535b099208493c7826ee4a64 ] While running under CONFIG_FORTIFY_SOURCE=y, syzkaller reported: memcpy: detected field-spanning write (size 129) of single field "target->sensf_res" at net/nfc/nci/ntf.c:260 (size 18) This appears to be a legitimate lack of bounds checking in nci_add_new_protocol(). Add the missing checks. Reported-by: syzbot+210e196cef4711b65139@syzkaller.appspotmail.com Link: https://lore.kernel.org/lkml/0000000000001c590f05ee7b3ff4@google.com Fixes: 019c4fbaa790 ("NFC: Add NCI multiple targets support") Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Link: https://lore.kernel.org/r/20221202214410.never.693-kees@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit e329e71013c9b5a4535b099208493c7826ee4a64 ]

While running under CONFIG_FORTIFY_SOURCE=y, syzkaller reported:

  memcpy: detected field-spanning write (size 129) of single field "target->sensf_res" at net/nfc/nci/ntf.c:260 (size 18)

This appears to be a legitimate lack of bounds checking in
nci_add_new_protocol(). Add the missing checks.

Reported-by: syzbot+210e196cef4711b65139@syzkaller.appspotmail.com
Link: https://lore.kernel.org/lkml/0000000000001c590f05ee7b3ff4@google.com
Fixes: 019c4fbaa790 ("NFC: Add NCI multiple targets support")
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20221202214410.never.693-kees@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
NFC: nci: fix memory leak in nci_rx_data_packet() 2022-12-08T10:22:59+00:00 Liu Shixin liushixin2@huawei.com 2022-11-18T08:24:19+00:00 1c12909a78202d0a6bc81eadde81a8c716b0cadc [ Upstream commit 53270fb0fd77fe786d8c07a0793981d797836b93 ] Syzbot reported a memory leak about skb: unreferenced object 0xffff88810e144e00 (size 240): comm "syz-executor284", pid 3701, jiffies 4294952403 (age 12.620s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff83ab79a9>] __alloc_skb+0x1f9/0x270 net/core/skbuff.c:497 [<ffffffff82a5cf64>] alloc_skb include/linux/skbuff.h:1267 [inline] [<ffffffff82a5cf64>] virtual_ncidev_write+0x24/0xe0 drivers/nfc/virtual_ncidev.c:116 [<ffffffff815f6503>] do_loop_readv_writev fs/read_write.c:759 [inline] [<ffffffff815f6503>] do_loop_readv_writev fs/read_write.c:743 [inline] [<ffffffff815f6503>] do_iter_write+0x253/0x300 fs/read_write.c:863 [<ffffffff815f66ed>] vfs_writev+0xdd/0x240 fs/read_write.c:934 [<ffffffff815f68f6>] do_writev+0xa6/0x1c0 fs/read_write.c:977 [<ffffffff848802d5>] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [<ffffffff848802d5>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 [<ffffffff84a00087>] entry_SYSCALL_64_after_hwframe+0x63/0xcd In nci_rx_data_packet(), if we don't get a valid conn_info, we will return directly but forget to release the skb. Reported-by: syzbot+cdb9a427d1bc08815104@syzkaller.appspotmail.com Fixes: 4aeee6871e8c ("NFC: nci: Add dynamic logical connections support") Signed-off-by: Liu Shixin <liushixin2@huawei.com> Link: https://lore.kernel.org/r/20221118082419.239475-1-liushixin2@huawei.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 53270fb0fd77fe786d8c07a0793981d797836b93 ]

Syzbot reported a memory leak about skb:

unreferenced object 0xffff88810e144e00 (size 240):
  comm "syz-executor284", pid 3701, jiffies 4294952403 (age 12.620s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff83ab79a9>] __alloc_skb+0x1f9/0x270 net/core/skbuff.c:497
    [<ffffffff82a5cf64>] alloc_skb include/linux/skbuff.h:1267 [inline]
    [<ffffffff82a5cf64>] virtual_ncidev_write+0x24/0xe0 drivers/nfc/virtual_ncidev.c:116
    [<ffffffff815f6503>] do_loop_readv_writev fs/read_write.c:759 [inline]
    [<ffffffff815f6503>] do_loop_readv_writev fs/read_write.c:743 [inline]
    [<ffffffff815f6503>] do_iter_write+0x253/0x300 fs/read_write.c:863
    [<ffffffff815f66ed>] vfs_writev+0xdd/0x240 fs/read_write.c:934
    [<ffffffff815f68f6>] do_writev+0xa6/0x1c0 fs/read_write.c:977
    [<ffffffff848802d5>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
    [<ffffffff848802d5>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
    [<ffffffff84a00087>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

In nci_rx_data_packet(), if we don't get a valid conn_info, we will return
directly but forget to release the skb.

Reported-by: syzbot+cdb9a427d1bc08815104@syzkaller.appspotmail.com
Fixes: 4aeee6871e8c ("NFC: nci: Add dynamic logical connections support")
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Link: https://lore.kernel.org/r/20221118082419.239475-1-liushixin2@huawei.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
nfc/nci: fix race with opening and closing 2022-12-08T10:22:58+00:00 Lin Ma linma@zju.edu.cn 2022-11-16T13:02:49+00:00 e00b42cbec158d7e04d2e25e1cdceff73e366c18 [ Upstream commit 0ad6bded175e829c2ca261529c9dce39a32a042d ] Previously we leverage NCI_UNREG and the lock inside nci_close_device to prevent the race condition between opening a device and closing a device. However, it still has problem because a failed opening command will erase the NCI_UNREG flag and allow another opening command to bypass the status checking. This fix corrects that by making sure the NCI_UNREG is held. Reported-by: syzbot+43475bf3cfbd6e41f5b7@syzkaller.appspotmail.com Fixes: 48b71a9e66c2 ("NFC: add NCI_UNREG flag to eliminate the race") Signed-off-by: Lin Ma <linma@zju.edu.cn> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 0ad6bded175e829c2ca261529c9dce39a32a042d ]

Previously we leverage NCI_UNREG and the lock inside nci_close_device to
prevent the race condition between opening a device and closing a
device. However, it still has problem because a failed opening command
will erase the NCI_UNREG flag and allow another opening command to
bypass the status checking.

This fix corrects that by making sure the NCI_UNREG is held.

Reported-by: syzbot+43475bf3cfbd6e41f5b7@syzkaller.appspotmail.com
Fixes: 48b71a9e66c2 ("NFC: add NCI_UNREG flag to eliminate the race")
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
NFC: NULL out the dev->rfkill to prevent UAF 2022-06-14T16:11:33+00:00 Lin Ma linma@zju.edu.cn 2022-04-12T05:32:08+00:00 fbf9c4c714d3cdeb98b6a18e4d057f931cad1d81 [ Upstream commit 1b0e81416a24d6e9b8c2341e22e8bf48f8b8bfc9 ] Commit 3e3b5dfcd16a ("NFC: reorder the logic in nfc_{un,}register_device") assumes the device_is_registered() in function nfc_dev_up() will help to check when the rfkill is unregistered. However, this check only take effect when device_del(&dev->dev) is done in nfc_unregister_device(). Hence, the rfkill object is still possible be dereferenced. The crash trace in latest kernel (5.18-rc2): [ 68.760105] ================================================================== [ 68.760330] BUG: KASAN: use-after-free in __lock_acquire+0x3ec1/0x6750 [ 68.760756] Read of size 8 at addr ffff888009c93018 by task fuzz/313 [ 68.760756] [ 68.760756] CPU: 0 PID: 313 Comm: fuzz Not tainted 5.18.0-rc2 #4 [ 68.760756] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 68.760756] Call Trace: [ 68.760756] <TASK> [ 68.760756] dump_stack_lvl+0x57/0x7d [ 68.760756] print_report.cold+0x5e/0x5db [ 68.760756] ? __lock_acquire+0x3ec1/0x6750 [ 68.760756] kasan_report+0xbe/0x1c0 [ 68.760756] ? __lock_acquire+0x3ec1/0x6750 [ 68.760756] __lock_acquire+0x3ec1/0x6750 [ 68.760756] ? lockdep_hardirqs_on_prepare+0x410/0x410 [ 68.760756] ? register_lock_class+0x18d0/0x18d0 [ 68.760756] lock_acquire+0x1ac/0x4f0 [ 68.760756] ? rfkill_blocked+0xe/0x60 [ 68.760756] ? lockdep_hardirqs_on_prepare+0x410/0x410 [ 68.760756] ? mutex_lock_io_nested+0x12c0/0x12c0 [ 68.760756] ? nla_get_range_signed+0x540/0x540 [ 68.760756] ? _raw_spin_lock_irqsave+0x4e/0x50 [ 68.760756] _raw_spin_lock_irqsave+0x39/0x50 [ 68.760756] ? rfkill_blocked+0xe/0x60 [ 68.760756] rfkill_blocked+0xe/0x60 [ 68.760756] nfc_dev_up+0x84/0x260 [ 68.760756] nfc_genl_dev_up+0x90/0xe0 [ 68.760756] genl_family_rcv_msg_doit+0x1f4/0x2f0 [ 68.760756] ? genl_family_rcv_msg_attrs_parse.constprop.0+0x230/0x230 [ 68.760756] ? security_capable+0x51/0x90 [ 68.760756] genl_rcv_msg+0x280/0x500 [ 68.760756] ? genl_get_cmd+0x3c0/0x3c0 [ 68.760756] ? lock_acquire+0x1ac/0x4f0 [ 68.760756] ? nfc_genl_dev_down+0xe0/0xe0 [ 68.760756] ? lockdep_hardirqs_on_prepare+0x410/0x410 [ 68.760756] netlink_rcv_skb+0x11b/0x340 [ 68.760756] ? genl_get_cmd+0x3c0/0x3c0 [ 68.760756] ? netlink_ack+0x9c0/0x9c0 [ 68.760756] ? netlink_deliver_tap+0x136/0xb00 [ 68.760756] genl_rcv+0x1f/0x30 [ 68.760756] netlink_unicast+0x430/0x710 [ 68.760756] ? memset+0x20/0x40 [ 68.760756] ? netlink_attachskb+0x740/0x740 [ 68.760756] ? __build_skb_around+0x1f4/0x2a0 [ 68.760756] netlink_sendmsg+0x75d/0xc00 [ 68.760756] ? netlink_unicast+0x710/0x710 [ 68.760756] ? netlink_unicast+0x710/0x710 [ 68.760756] sock_sendmsg+0xdf/0x110 [ 68.760756] __sys_sendto+0x19e/0x270 [ 68.760756] ? __ia32_sys_getpeername+0xa0/0xa0 [ 68.760756] ? fd_install+0x178/0x4c0 [ 68.760756] ? fd_install+0x195/0x4c0 [ 68.760756] ? kernel_fpu_begin_mask+0x1c0/0x1c0 [ 68.760756] __x64_sys_sendto+0xd8/0x1b0 [ 68.760756] ? lockdep_hardirqs_on+0xbf/0x130 [ 68.760756] ? syscall_enter_from_user_mode+0x1d/0x50 [ 68.760756] do_syscall_64+0x3b/0x90 [ 68.760756] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 68.760756] RIP: 0033:0x7f67fb50e6b3 ... [ 68.760756] RSP: 002b:00007f67fa91fe90 EFLAGS: 00000293 ORIG_RAX: 000000000000002c [ 68.760756] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f67fb50e6b3 [ 68.760756] RDX: 000000000000001c RSI: 0000559354603090 RDI: 0000000000000003 [ 68.760756] RBP: 00007f67fa91ff00 R08: 00007f67fa91fedc R09: 000000000000000c [ 68.760756] R10: 0000000000000000 R11: 0000000000000293 R12: 00007ffe824d496e [ 68.760756] R13: 00007ffe824d496f R14: 00007f67fa120000 R15: 0000000000000003 [ 68.760756] </TASK> [ 68.760756] [ 68.760756] Allocated by task 279: [ 68.760756] kasan_save_stack+0x1e/0x40 [ 68.760756] __kasan_kmalloc+0x81/0xa0 [ 68.760756] rfkill_alloc+0x7f/0x280 [ 68.760756] nfc_register_device+0xa3/0x1a0 [ 68.760756] nci_register_device+0x77a/0xad0 [ 68.760756] nfcmrvl_nci_register_dev+0x20b/0x2c0 [ 68.760756] nfcmrvl_nci_uart_open+0xf2/0x1dd [ 68.760756] nci_uart_tty_ioctl+0x2c3/0x4a0 [ 68.760756] tty_ioctl+0x764/0x1310 [ 68.760756] __x64_sys_ioctl+0x122/0x190 [ 68.760756] do_syscall_64+0x3b/0x90 [ 68.760756] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 68.760756] [ 68.760756] Freed by task 314: [ 68.760756] kasan_save_stack+0x1e/0x40 [ 68.760756] kasan_set_track+0x21/0x30 [ 68.760756] kasan_set_free_info+0x20/0x30 [ 68.760756] __kasan_slab_free+0x108/0x170 [ 68.760756] kfree+0xb0/0x330 [ 68.760756] device_release+0x96/0x200 [ 68.760756] kobject_put+0xf9/0x1d0 [ 68.760756] nfc_unregister_device+0x77/0x190 [ 68.760756] nfcmrvl_nci_unregister_dev+0x88/0xd0 [ 68.760756] nci_uart_tty_close+0xdf/0x180 [ 68.760756] tty_ldisc_kill+0x73/0x110 [ 68.760756] tty_ldisc_hangup+0x281/0x5b0 [ 68.760756] __tty_hangup.part.0+0x431/0x890 [ 68.760756] tty_release+0x3a8/0xc80 [ 68.760756] __fput+0x1f0/0x8c0 [ 68.760756] task_work_run+0xc9/0x170 [ 68.760756] exit_to_user_mode_prepare+0x194/0x1a0 [ 68.760756] syscall_exit_to_user_mode+0x19/0x50 [ 68.760756] do_syscall_64+0x48/0x90 [ 68.760756] entry_SYSCALL_64_after_hwframe+0x44/0xae This patch just add the null out of dev->rfkill to make sure such dereference cannot happen. This is safe since the device_lock() already protect the check/write from data race. Fixes: 3e3b5dfcd16a ("NFC: reorder the logic in nfc_{un,}register_device") Signed-off-by: Lin Ma <linma@zju.edu.cn> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 1b0e81416a24d6e9b8c2341e22e8bf48f8b8bfc9 ]

Commit 3e3b5dfcd16a ("NFC: reorder the logic in nfc_{un,}register_device")
assumes the device_is_registered() in function nfc_dev_up() will help
to check when the rfkill is unregistered. However, this check only
take effect when device_del(&dev->dev) is done in nfc_unregister_device().
Hence, the rfkill object is still possible be dereferenced.

The crash trace in latest kernel (5.18-rc2):

[   68.760105] ==================================================================
[   68.760330] BUG: KASAN: use-after-free in __lock_acquire+0x3ec1/0x6750
[   68.760756] Read of size 8 at addr ffff888009c93018 by task fuzz/313
[   68.760756]
[   68.760756] CPU: 0 PID: 313 Comm: fuzz Not tainted 5.18.0-rc2 #4
[   68.760756] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[   68.760756] Call Trace:
[   68.760756]  <TASK>
[   68.760756]  dump_stack_lvl+0x57/0x7d
[   68.760756]  print_report.cold+0x5e/0x5db
[   68.760756]  ? __lock_acquire+0x3ec1/0x6750
[   68.760756]  kasan_report+0xbe/0x1c0
[   68.760756]  ? __lock_acquire+0x3ec1/0x6750
[   68.760756]  __lock_acquire+0x3ec1/0x6750
[   68.760756]  ? lockdep_hardirqs_on_prepare+0x410/0x410
[   68.760756]  ? register_lock_class+0x18d0/0x18d0
[   68.760756]  lock_acquire+0x1ac/0x4f0
[   68.760756]  ? rfkill_blocked+0xe/0x60
[   68.760756]  ? lockdep_hardirqs_on_prepare+0x410/0x410
[   68.760756]  ? mutex_lock_io_nested+0x12c0/0x12c0
[   68.760756]  ? nla_get_range_signed+0x540/0x540
[   68.760756]  ? _raw_spin_lock_irqsave+0x4e/0x50
[   68.760756]  _raw_spin_lock_irqsave+0x39/0x50
[   68.760756]  ? rfkill_blocked+0xe/0x60
[   68.760756]  rfkill_blocked+0xe/0x60
[   68.760756]  nfc_dev_up+0x84/0x260
[   68.760756]  nfc_genl_dev_up+0x90/0xe0
[   68.760756]  genl_family_rcv_msg_doit+0x1f4/0x2f0
[   68.760756]  ? genl_family_rcv_msg_attrs_parse.constprop.0+0x230/0x230
[   68.760756]  ? security_capable+0x51/0x90
[   68.760756]  genl_rcv_msg+0x280/0x500
[   68.760756]  ? genl_get_cmd+0x3c0/0x3c0
[   68.760756]  ? lock_acquire+0x1ac/0x4f0
[   68.760756]  ? nfc_genl_dev_down+0xe0/0xe0
[   68.760756]  ? lockdep_hardirqs_on_prepare+0x410/0x410
[   68.760756]  netlink_rcv_skb+0x11b/0x340
[   68.760756]  ? genl_get_cmd+0x3c0/0x3c0
[   68.760756]  ? netlink_ack+0x9c0/0x9c0
[   68.760756]  ? netlink_deliver_tap+0x136/0xb00
[   68.760756]  genl_rcv+0x1f/0x30
[   68.760756]  netlink_unicast+0x430/0x710
[   68.760756]  ? memset+0x20/0x40
[   68.760756]  ? netlink_attachskb+0x740/0x740
[   68.760756]  ? __build_skb_around+0x1f4/0x2a0
[   68.760756]  netlink_sendmsg+0x75d/0xc00
[   68.760756]  ? netlink_unicast+0x710/0x710
[   68.760756]  ? netlink_unicast+0x710/0x710
[   68.760756]  sock_sendmsg+0xdf/0x110
[   68.760756]  __sys_sendto+0x19e/0x270
[   68.760756]  ? __ia32_sys_getpeername+0xa0/0xa0
[   68.760756]  ? fd_install+0x178/0x4c0
[   68.760756]  ? fd_install+0x195/0x4c0
[   68.760756]  ? kernel_fpu_begin_mask+0x1c0/0x1c0
[   68.760756]  __x64_sys_sendto+0xd8/0x1b0
[   68.760756]  ? lockdep_hardirqs_on+0xbf/0x130
[   68.760756]  ? syscall_enter_from_user_mode+0x1d/0x50
[   68.760756]  do_syscall_64+0x3b/0x90
[   68.760756]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[   68.760756] RIP: 0033:0x7f67fb50e6b3
...
[   68.760756] RSP: 002b:00007f67fa91fe90 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
[   68.760756] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f67fb50e6b3
[   68.760756] RDX: 000000000000001c RSI: 0000559354603090 RDI: 0000000000000003
[   68.760756] RBP: 00007f67fa91ff00 R08: 00007f67fa91fedc R09: 000000000000000c
[   68.760756] R10: 0000000000000000 R11: 0000000000000293 R12: 00007ffe824d496e
[   68.760756] R13: 00007ffe824d496f R14: 00007f67fa120000 R15: 0000000000000003

[   68.760756]  </TASK>
[   68.760756]
[   68.760756] Allocated by task 279:
[   68.760756]  kasan_save_stack+0x1e/0x40
[   68.760756]  __kasan_kmalloc+0x81/0xa0
[   68.760756]  rfkill_alloc+0x7f/0x280
[   68.760756]  nfc_register_device+0xa3/0x1a0
[   68.760756]  nci_register_device+0x77a/0xad0
[   68.760756]  nfcmrvl_nci_register_dev+0x20b/0x2c0
[   68.760756]  nfcmrvl_nci_uart_open+0xf2/0x1dd
[   68.760756]  nci_uart_tty_ioctl+0x2c3/0x4a0
[   68.760756]  tty_ioctl+0x764/0x1310
[   68.760756]  __x64_sys_ioctl+0x122/0x190
[   68.760756]  do_syscall_64+0x3b/0x90
[   68.760756]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[   68.760756]
[   68.760756] Freed by task 314:
[   68.760756]  kasan_save_stack+0x1e/0x40
[   68.760756]  kasan_set_track+0x21/0x30
[   68.760756]  kasan_set_free_info+0x20/0x30
[   68.760756]  __kasan_slab_free+0x108/0x170
[   68.760756]  kfree+0xb0/0x330
[   68.760756]  device_release+0x96/0x200
[   68.760756]  kobject_put+0xf9/0x1d0
[   68.760756]  nfc_unregister_device+0x77/0x190
[   68.760756]  nfcmrvl_nci_unregister_dev+0x88/0xd0
[   68.760756]  nci_uart_tty_close+0xdf/0x180
[   68.760756]  tty_ldisc_kill+0x73/0x110
[   68.760756]  tty_ldisc_hangup+0x281/0x5b0
[   68.760756]  __tty_hangup.part.0+0x431/0x890
[   68.760756]  tty_release+0x3a8/0xc80
[   68.760756]  __fput+0x1f0/0x8c0
[   68.760756]  task_work_run+0xc9/0x170
[   68.760756]  exit_to_user_mode_prepare+0x194/0x1a0
[   68.760756]  syscall_exit_to_user_mode+0x19/0x50
[   68.760756]  do_syscall_64+0x48/0x90
[   68.760756]  entry_SYSCALL_64_after_hwframe+0x44/0xae

This patch just add the null out of dev->rfkill to make sure such
dereference cannot happen. This is safe since the device_lock() already
protect the check/write from data race.

Fixes: 3e3b5dfcd16a ("NFC: reorder the logic in nfc_{un,}register_device")
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
NFC: nci: fix sleep in atomic context bugs caused by nci_skb_alloc 2022-05-25T07:14:36+00:00 Duoming Zhou duoming@zju.edu.cn 2022-05-17T01:25:30+00:00 3277789f332ed34d46d35ee84992fd643f48aa4a [ Upstream commit 23dd4581350d4ffa23d58976ec46408f8f4c1e16 ] There are sleep in atomic context bugs when the request to secure element of st-nci is timeout. The root cause is that nci_skb_alloc with GFP_KERNEL parameter is called in st_nci_se_wt_timeout which is a timer handler. The call paths that could trigger bugs are shown below: (interrupt context 1) st_nci_se_wt_timeout nci_hci_send_event nci_hci_send_data nci_skb_alloc(..., GFP_KERNEL) //may sleep (interrupt context 2) st_nci_se_wt_timeout nci_hci_send_event nci_hci_send_data nci_send_data nci_queue_tx_data_frags nci_skb_alloc(..., GFP_KERNEL) //may sleep This patch changes allocation mode of nci_skb_alloc from GFP_KERNEL to GFP_ATOMIC in order to prevent atomic context sleeping. The GFP_ATOMIC flag makes memory allocation operation could be used in atomic context. Fixes: ed06aeefdac3 ("nfc: st-nci: Rename st21nfcb to st-nci") Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Link: https://lore.kernel.org/r/20220517012530.75714-1-duoming@zju.edu.cn Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 23dd4581350d4ffa23d58976ec46408f8f4c1e16 ]

There are sleep in atomic context bugs when the request to secure
element of st-nci is timeout. The root cause is that nci_skb_alloc
with GFP_KERNEL parameter is called in st_nci_se_wt_timeout which is
a timer handler. The call paths that could trigger bugs are shown below:

    (interrupt context 1)
st_nci_se_wt_timeout
  nci_hci_send_event
    nci_hci_send_data
      nci_skb_alloc(..., GFP_KERNEL) //may sleep

   (interrupt context 2)
st_nci_se_wt_timeout
  nci_hci_send_event
    nci_hci_send_data
      nci_send_data
        nci_queue_tx_data_frags
          nci_skb_alloc(..., GFP_KERNEL) //may sleep

This patch changes allocation mode of nci_skb_alloc from GFP_KERNEL to
GFP_ATOMIC in order to prevent atomic context sleeping. The GFP_ATOMIC
flag makes memory allocation operation could be used in atomic context.

Fixes: ed06aeefdac3 ("nfc: st-nci: Rename st21nfcb to st-nci")
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220517012530.75714-1-duoming@zju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
NFC: netlink: fix sleep in atomic bug when firmware download timeout 2022-05-12T10:23:44+00:00 Duoming Zhou duoming@zju.edu.cn 2022-05-04T05:58:47+00:00 01d4363dd7176fd780066cd020f66c0f55c4b6f9 commit 4071bf121d59944d5cd2238de0642f3d7995a997 upstream. There are sleep in atomic bug that could cause kernel panic during firmware download process. The root cause is that nlmsg_new with GFP_KERNEL parameter is called in fw_dnld_timeout which is a timer handler. The call trace is shown below: BUG: sleeping function called from invalid context at include/linux/sched/mm.h:265 Call Trace: kmem_cache_alloc_node __alloc_skb nfc_genl_fw_download_done call_timer_fn __run_timers.part.0 run_timer_softirq __do_softirq ... The nlmsg_new with GFP_KERNEL parameter may sleep during memory allocation process, and the timer handler is run as the result of a "software interrupt" that should not call any other function that could sleep. This patch changes allocation mode of netlink message from GFP_KERNEL to GFP_ATOMIC in order to prevent sleep in atomic bug. The GFP_ATOMIC flag makes memory allocation operation could be used in atomic context. Fixes: 9674da8759df ("NFC: Add firmware upload netlink command") Fixes: 9ea7187c53f6 ("NFC: netlink: Rename CMD_FW_UPLOAD to CMD_FW_DOWNLOAD") Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Link: https://lore.kernel.org/r/20220504055847.38026-1-duoming@zju.edu.cn Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 4071bf121d59944d5cd2238de0642f3d7995a997 upstream.

There are sleep in atomic bug that could cause kernel panic during
firmware download process. The root cause is that nlmsg_new with
GFP_KERNEL parameter is called in fw_dnld_timeout which is a timer
handler. The call trace is shown below:

BUG: sleeping function called from invalid context at include/linux/sched/mm.h:265
Call Trace:
kmem_cache_alloc_node
__alloc_skb
nfc_genl_fw_download_done
call_timer_fn
__run_timers.part.0
run_timer_softirq
__do_softirq
...

The nlmsg_new with GFP_KERNEL parameter may sleep during memory
allocation process, and the timer handler is run as the result of
a "software interrupt" that should not call any other function
that could sleep.

This patch changes allocation mode of netlink message from GFP_KERNEL
to GFP_ATOMIC in order to prevent sleep in atomic bug. The GFP_ATOMIC
flag makes memory allocation operation could be used in atomic context.

Fixes: 9674da8759df ("NFC: Add firmware upload netlink command")
Fixes: 9ea7187c53f6 ("NFC: netlink: Rename CMD_FW_UPLOAD to CMD_FW_DOWNLOAD")
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220504055847.38026-1-duoming@zju.edu.cn
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
nfc: replace improper check device_is_registered() in netlink related functions 2022-05-12T10:23:44+00:00 Duoming Zhou duoming@zju.edu.cn 2022-04-29T12:45:50+00:00 85aecdef77f9c5b5c0d8988db6681960f0d46ab3 commit da5c0f119203ad9728920456a0f52a6d850c01cd upstream. The device_is_registered() in nfc core is used to check whether nfc device is registered in netlink related functions such as nfc_fw_download(), nfc_dev_up() and so on. Although device_is_registered() is protected by device_lock, there is still a race condition between device_del() and device_is_registered(). The root cause is that kobject_del() in device_del() is not protected by device_lock. (cleanup task) | (netlink task) | nfc_unregister_device | nfc_fw_download device_del | device_lock ... | if (!device_is_registered)//(1) kobject_del//(2) | ... ... | device_unlock The device_is_registered() returns the value of state_in_sysfs and the state_in_sysfs is set to zero in kobject_del(). If we pass check in position (1), then set zero in position (2). As a result, the check in position (1) is useless. This patch uses bool variable instead of device_is_registered() to judge whether the nfc device is registered, which is well synchronized. Fixes: 3e256b8f8dfa ("NFC: add nfc subsystem core") Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit da5c0f119203ad9728920456a0f52a6d850c01cd upstream.

The device_is_registered() in nfc core is used to check whether
nfc device is registered in netlink related functions such as
nfc_fw_download(), nfc_dev_up() and so on. Although device_is_registered()
is protected by device_lock, there is still a race condition between
device_del() and device_is_registered(). The root cause is that
kobject_del() in device_del() is not protected by device_lock.

   (cleanup task)         |     (netlink task)
                          |
nfc_unregister_device     | nfc_fw_download
 device_del               |  device_lock
  ...                     |   if (!device_is_registered)//(1)
  kobject_del//(2)        |   ...
 ...                      |  device_unlock

The device_is_registered() returns the value of state_in_sysfs and
the state_in_sysfs is set to zero in kobject_del(). If we pass check in
position (1), then set zero in position (2). As a result, the check
in position (1) is useless.

This patch uses bool variable instead of device_is_registered() to judge
whether the nfc device is registered, which is well synchronized.

Fixes: 3e256b8f8dfa ("NFC: add nfc subsystem core")
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
nfc: nci: add flush_workqueue to prevent uaf 2022-04-20T07:19:35+00:00 Lin Ma linma@zju.edu.cn 2022-04-12T16:04:30+00:00 5c63ad2b0a267a524c12c88acb1ba9c2d109a801 [ Upstream commit ef27324e2cb7bb24542d6cb2571740eefe6b00dc ] Our detector found a concurrent use-after-free bug when detaching an NCI device. The main reason for this bug is the unexpected scheduling between the used delayed mechanism (timer and workqueue). The race can be demonstrated below: Thread-1 Thread-2 | nci_dev_up() | nci_open_device() | __nci_request(nci_reset_req) | nci_send_cmd | queue_work(cmd_work) nci_unregister_device() | nci_close_device() | ... del_timer_sync(cmd_timer)[1] | ... | Worker nci_free_device() | nci_cmd_work() kfree(ndev)[3] | mod_timer(cmd_timer)[2] In short, the cleanup routine thought that the cmd_timer has already been detached by [1] but the mod_timer can re-attach the timer [2], even it is already released [3], resulting in UAF. This UAF is easy to trigger, crash trace by POC is like below [ 66.703713] ================================================================== [ 66.703974] BUG: KASAN: use-after-free in enqueue_timer+0x448/0x490 [ 66.703974] Write of size 8 at addr ffff888009fb7058 by task kworker/u4:1/33 [ 66.703974] [ 66.703974] CPU: 1 PID: 33 Comm: kworker/u4:1 Not tainted 5.18.0-rc2 #5 [ 66.703974] Workqueue: nfc2_nci_cmd_wq nci_cmd_work [ 66.703974] Call Trace: [ 66.703974] <TASK> [ 66.703974] dump_stack_lvl+0x57/0x7d [ 66.703974] print_report.cold+0x5e/0x5db [ 66.703974] ? enqueue_timer+0x448/0x490 [ 66.703974] kasan_report+0xbe/0x1c0 [ 66.703974] ? enqueue_timer+0x448/0x490 [ 66.703974] enqueue_timer+0x448/0x490 [ 66.703974] __mod_timer+0x5e6/0xb80 [ 66.703974] ? mark_held_locks+0x9e/0xe0 [ 66.703974] ? try_to_del_timer_sync+0xf0/0xf0 [ 66.703974] ? lockdep_hardirqs_on_prepare+0x17b/0x410 [ 66.703974] ? queue_work_on+0x61/0x80 [ 66.703974] ? lockdep_hardirqs_on+0xbf/0x130 [ 66.703974] process_one_work+0x8bb/0x1510 [ 66.703974] ? lockdep_hardirqs_on_prepare+0x410/0x410 [ 66.703974] ? pwq_dec_nr_in_flight+0x230/0x230 [ 66.703974] ? rwlock_bug.part.0+0x90/0x90 [ 66.703974] ? _raw_spin_lock_irq+0x41/0x50 [ 66.703974] worker_thread+0x575/0x1190 [ 66.703974] ? process_one_work+0x1510/0x1510 [ 66.703974] kthread+0x2a0/0x340 [ 66.703974] ? kthread_complete_and_exit+0x20/0x20 [ 66.703974] ret_from_fork+0x22/0x30 [ 66.703974] </TASK> [ 66.703974] [ 66.703974] Allocated by task 267: [ 66.703974] kasan_save_stack+0x1e/0x40 [ 66.703974] __kasan_kmalloc+0x81/0xa0 [ 66.703974] nci_allocate_device+0xd3/0x390 [ 66.703974] nfcmrvl_nci_register_dev+0x183/0x2c0 [ 66.703974] nfcmrvl_nci_uart_open+0xf2/0x1dd [ 66.703974] nci_uart_tty_ioctl+0x2c3/0x4a0 [ 66.703974] tty_ioctl+0x764/0x1310 [ 66.703974] __x64_sys_ioctl+0x122/0x190 [ 66.703974] do_syscall_64+0x3b/0x90 [ 66.703974] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 66.703974] [ 66.703974] Freed by task 406: [ 66.703974] kasan_save_stack+0x1e/0x40 [ 66.703974] kasan_set_track+0x21/0x30 [ 66.703974] kasan_set_free_info+0x20/0x30 [ 66.703974] __kasan_slab_free+0x108/0x170 [ 66.703974] kfree+0xb0/0x330 [ 66.703974] nfcmrvl_nci_unregister_dev+0x90/0xd0 [ 66.703974] nci_uart_tty_close+0xdf/0x180 [ 66.703974] tty_ldisc_kill+0x73/0x110 [ 66.703974] tty_ldisc_hangup+0x281/0x5b0 [ 66.703974] __tty_hangup.part.0+0x431/0x890 [ 66.703974] tty_release+0x3a8/0xc80 [ 66.703974] __fput+0x1f0/0x8c0 [ 66.703974] task_work_run+0xc9/0x170 [ 66.703974] exit_to_user_mode_prepare+0x194/0x1a0 [ 66.703974] syscall_exit_to_user_mode+0x19/0x50 [ 66.703974] do_syscall_64+0x48/0x90 [ 66.703974] entry_SYSCALL_64_after_hwframe+0x44/0xae To fix the UAF, this patch adds flush_workqueue() to ensure the nci_cmd_work is finished before the following del_timer_sync. This combination will promise the timer is actually detached. Fixes: 6a2968aaf50c ("NFC: basic NCI protocol implementation") Signed-off-by: Lin Ma <linma@zju.edu.cn> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit ef27324e2cb7bb24542d6cb2571740eefe6b00dc ]

Our detector found a concurrent use-after-free bug when detaching an
NCI device. The main reason for this bug is the unexpected scheduling
between the used delayed mechanism (timer and workqueue).

The race can be demonstrated below:

Thread-1                           Thread-2
                                 | nci_dev_up()
                                 |   nci_open_device()
                                 |     __nci_request(nci_reset_req)
                                 |       nci_send_cmd
                                 |         queue_work(cmd_work)
nci_unregister_device()          |
  nci_close_device()             | ...
    del_timer_sync(cmd_timer)[1] |
...                              | Worker
nci_free_device()                | nci_cmd_work()
  kfree(ndev)[3]                 |   mod_timer(cmd_timer)[2]

In short, the cleanup routine thought that the cmd_timer has already
been detached by [1] but the mod_timer can re-attach the timer [2], even
it is already released [3], resulting in UAF.

This UAF is easy to trigger, crash trace by POC is like below

[   66.703713] ==================================================================
[   66.703974] BUG: KASAN: use-after-free in enqueue_timer+0x448/0x490
[   66.703974] Write of size 8 at addr ffff888009fb7058 by task kworker/u4:1/33
[   66.703974]
[   66.703974] CPU: 1 PID: 33 Comm: kworker/u4:1 Not tainted 5.18.0-rc2 #5
[   66.703974] Workqueue: nfc2_nci_cmd_wq nci_cmd_work
[   66.703974] Call Trace:
[   66.703974]  <TASK>
[   66.703974]  dump_stack_lvl+0x57/0x7d
[   66.703974]  print_report.cold+0x5e/0x5db
[   66.703974]  ? enqueue_timer+0x448/0x490
[   66.703974]  kasan_report+0xbe/0x1c0
[   66.703974]  ? enqueue_timer+0x448/0x490
[   66.703974]  enqueue_timer+0x448/0x490
[   66.703974]  __mod_timer+0x5e6/0xb80
[   66.703974]  ? mark_held_locks+0x9e/0xe0
[   66.703974]  ? try_to_del_timer_sync+0xf0/0xf0
[   66.703974]  ? lockdep_hardirqs_on_prepare+0x17b/0x410
[   66.703974]  ? queue_work_on+0x61/0x80
[   66.703974]  ? lockdep_hardirqs_on+0xbf/0x130
[   66.703974]  process_one_work+0x8bb/0x1510
[   66.703974]  ? lockdep_hardirqs_on_prepare+0x410/0x410
[   66.703974]  ? pwq_dec_nr_in_flight+0x230/0x230
[   66.703974]  ? rwlock_bug.part.0+0x90/0x90
[   66.703974]  ? _raw_spin_lock_irq+0x41/0x50
[   66.703974]  worker_thread+0x575/0x1190
[   66.703974]  ? process_one_work+0x1510/0x1510
[   66.703974]  kthread+0x2a0/0x340
[   66.703974]  ? kthread_complete_and_exit+0x20/0x20
[   66.703974]  ret_from_fork+0x22/0x30
[   66.703974]  </TASK>
[   66.703974]
[   66.703974] Allocated by task 267:
[   66.703974]  kasan_save_stack+0x1e/0x40
[   66.703974]  __kasan_kmalloc+0x81/0xa0
[   66.703974]  nci_allocate_device+0xd3/0x390
[   66.703974]  nfcmrvl_nci_register_dev+0x183/0x2c0
[   66.703974]  nfcmrvl_nci_uart_open+0xf2/0x1dd
[   66.703974]  nci_uart_tty_ioctl+0x2c3/0x4a0
[   66.703974]  tty_ioctl+0x764/0x1310
[   66.703974]  __x64_sys_ioctl+0x122/0x190
[   66.703974]  do_syscall_64+0x3b/0x90
[   66.703974]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[   66.703974]
[   66.703974] Freed by task 406:
[   66.703974]  kasan_save_stack+0x1e/0x40
[   66.703974]  kasan_set_track+0x21/0x30
[   66.703974]  kasan_set_free_info+0x20/0x30
[   66.703974]  __kasan_slab_free+0x108/0x170
[   66.703974]  kfree+0xb0/0x330
[   66.703974]  nfcmrvl_nci_unregister_dev+0x90/0xd0
[   66.703974]  nci_uart_tty_close+0xdf/0x180
[   66.703974]  tty_ldisc_kill+0x73/0x110
[   66.703974]  tty_ldisc_hangup+0x281/0x5b0
[   66.703974]  __tty_hangup.part.0+0x431/0x890
[   66.703974]  tty_release+0x3a8/0xc80
[   66.703974]  __fput+0x1f0/0x8c0
[   66.703974]  task_work_run+0xc9/0x170
[   66.703974]  exit_to_user_mode_prepare+0x194/0x1a0
[   66.703974]  syscall_exit_to_user_mode+0x19/0x50
[   66.703974]  do_syscall_64+0x48/0x90
[   66.703974]  entry_SYSCALL_64_after_hwframe+0x44/0xae

To fix the UAF, this patch adds flush_workqueue() to ensure the
nci_cmd_work is finished before the following del_timer_sync.
This combination will promise the timer is actually detached.

Fixes: 6a2968aaf50c ("NFC: basic NCI protocol implementation")
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>