linux-toradex.git/net/nfc/nci, branch master Linux kernel for Apalis and Colibri modules nfc: fix use-after-free in nfc_get_local_general_bytes 2026-09-23T20:13:17+00:00 Luxiao Xu rakukuip@gmail.com 2026-09-09T05:19:24+00:00 dcab71a7011918f6fdba7adcec02d217dcb84b8d Commit 6709d4b7bc2e ("net: nfc: Fix use-after-free caused by nfc_llcp_find_local") attempted to fix a use-after-free (UAF) issue by invoking nfc_llcp_local_put(local) after accessing local->gb. However, if the reference count drops to zero, local is freed immediately, leading to a use-after-free when callers access the returned pointer. Alternative approaches using dynamic allocation (e.g. kmemdup) introduced memory leaks because callers consistently treat the returned pointer as borrowed memory. Fix this properly by refactoring nfc_llcp_general_bytes() and nfc_get_local_general_bytes() to accept a caller-provided output buffer (out_gb) and its maximum length (gb_max_len). The general bytes are safely copied into out_gb before calling nfc_llcp_local_put(local), ensuring safe lifetime management without ownership transfer complications. Update all callers across drivers (microread, pn533, pn544, st21nfca, digital_dep, and nci) to provide their own destination buffers and pass them to nfc_get_local_general_bytes(). Fixes: 6709d4b7bc2e ("net: nfc: Fix use-after-free caused by nfc_llcp_find_local") Cc: stable@vger.kernel.org Reported-by: Vega <vega@nebusec.ai> Assisted-by: LLM Signed-off-by: Luxiao Xu <rakukuip@gmail.com> Signed-off-by: Ren Wei <weir@nebusec.ai> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/3cbaac3bee23f8ff3a3284ed32d347696eb1d208.1788841683.git.rakukuip@gmail.com Signed-off-by: David Heidelberg <david@ixit.cz> 
Commit 6709d4b7bc2e ("net: nfc: Fix use-after-free caused by
nfc_llcp_find_local") attempted to fix a use-after-free (UAF) issue by
invoking nfc_llcp_local_put(local) after accessing local->gb. However,
if the reference count drops to zero, local is freed immediately,
leading to a use-after-free when callers access the returned pointer.
Alternative approaches using dynamic allocation (e.g. kmemdup) introduced
memory leaks because callers consistently treat the returned pointer as
borrowed memory.

Fix this properly by refactoring nfc_llcp_general_bytes() and
nfc_get_local_general_bytes() to accept a caller-provided output buffer
(out_gb) and its maximum length (gb_max_len). The general bytes are
safely copied into out_gb before calling nfc_llcp_local_put(local),
ensuring safe lifetime management without ownership transfer complications.

Update all callers across drivers (microread, pn533, pn544, st21nfca,
digital_dep, and nci) to provide their own destination buffers and pass
them to nfc_get_local_general_bytes().

Fixes: 6709d4b7bc2e ("net: nfc: Fix use-after-free caused by nfc_llcp_find_local")
Cc: stable@vger.kernel.org
Reported-by: Vega <vega@nebusec.ai>
Assisted-by: LLM
Signed-off-by: Luxiao Xu <rakukuip@gmail.com>
Signed-off-by: Ren Wei <weir@nebusec.ai>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/3cbaac3bee23f8ff3a3284ed32d347696eb1d208.1788841683.git.rakukuip@gmail.com
Signed-off-by: David Heidelberg <david@ixit.cz>
nfc: nci: free destination parameters when closing a connection 2026-08-11T16:10:04+00:00 Linmao Li lilinmao@kylinos.cn 2026-07-21T02:35:18+00:00 2e65bafdfd3a8bba972b3d17b6a57816557530fc When a connection is closed, nci_core_conn_close_rsp_packet() frees conn_info but not conn_info->dest_params, which is a separate devm allocation. Each connect/close cycle leaks one dest_params until the NFC device is removed. Free dest_params along with conn_info. Fixes: 9b8d1a4cf2aa ("nfc: nci: Add an additional parameter to identify a connection id") Cc: stable@vger.kernel.org Signed-off-by: Linmao Li <lilinmao@kylinos.cn> Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev> Link: https://patch.msgid.link/20260721023518.1697625-1-lilinmao@kylinos.cn Signed-off-by: David Heidelberg <david@ixit.cz> 
When a connection is closed, nci_core_conn_close_rsp_packet() frees
conn_info but not conn_info->dest_params, which is a separate devm
allocation. Each connect/close cycle leaks one dest_params until the
NFC device is removed. Free dest_params along with conn_info.

Fixes: 9b8d1a4cf2aa ("nfc: nci: Add an additional parameter to identify a connection id")
Cc: stable@vger.kernel.org
Signed-off-by: Linmao Li <lilinmao@kylinos.cn>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Link: https://patch.msgid.link/20260721023518.1697625-1-lilinmao@kylinos.cn
Signed-off-by: David Heidelberg <david@ixit.cz>
nfc: nci: fix use of uninitialized memory in CORE_INIT_RSP parsing 2026-08-11T16:10:04+00:00 Yun Zhou yun.zhou@windriver.com 2026-05-27T05:26:25+00:00 d56575a2595ee1f597f39e8a1cfb67ed3501678d nci_core_init_rsp_packet_v1() and nci_core_init_rsp_packet_v2() parse the CORE_INIT_RSP packet without validating that the skb contains enough data. A malformed response (e.g. injected via virtual_ncidev) can declare a large num_supported_rf_interfaces while providing insufficient data, causing reads of uninitialized slab memory. This is later used in nci_init_complete_req(), triggering a KMSAN uninit-value warning. Add skb length checks before accessing packet fields: - Validate the skb has at least 1 byte for the status field. - Validate the skb can hold the fixed-size header before parsing. - In v2, bounds-check each variable-length rf_interface entry and its extension parameters within the parsing loop. - In v1, verify the skb is large enough for both the variable-length rf_interfaces array and the trailing rsp_2 structure. Reported-by: syzbot+46ca2592193f2fb3debc@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=46ca2592193f2fb3debc Fixes: bcd684aace34 ("net/nfc/nci: Support NCI 2.x initial sequence") Signed-off-by: Yun Zhou <yun.zhou@windriver.com> Link: https://patch.msgid.link/20260527052625.3309581-1-yun.zhou@windriver.com Signed-off-by: David Heidelberg <david@ixit.cz> 
nci_core_init_rsp_packet_v1() and nci_core_init_rsp_packet_v2() parse
the CORE_INIT_RSP packet without validating that the skb contains
enough data. A malformed response (e.g. injected via virtual_ncidev)
can declare a large num_supported_rf_interfaces while providing
insufficient data, causing reads of uninitialized slab memory. This
is later used in nci_init_complete_req(), triggering a KMSAN
uninit-value warning.

Add skb length checks before accessing packet fields:
- Validate the skb has at least 1 byte for the status field.
- Validate the skb can hold the fixed-size header before parsing.
- In v2, bounds-check each variable-length rf_interface entry and its
  extension parameters within the parsing loop.
- In v1, verify the skb is large enough for both the variable-length
  rf_interfaces array and the trailing rsp_2 structure.

Reported-by: syzbot+46ca2592193f2fb3debc@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=46ca2592193f2fb3debc
Fixes: bcd684aace34 ("net/nfc/nci: Support NCI 2.x initial sequence")
Signed-off-by: Yun Zhou <yun.zhou@windriver.com>
Link: https://patch.msgid.link/20260527052625.3309581-1-yun.zhou@windriver.com
Signed-off-by: David Heidelberg <david@ixit.cz>
nfc: nci: fix uninit-value in the RF discover/activated NTF handlers 2026-08-11T16:10:03+00:00 Samuel Page sam@bynar.io 2026-06-26T09:03:01+00:00 8cbe06c1e699c0a165dae5093a2550e65f914818 nci_rf_discover_ntf_packet() and nci_rf_intf_activated_ntf_packet() each parse a notification into an on-stack struct (nci_rf_discover_ntf / nci_rf_intf_activated_ntf) that is not initialised. The RF technology-specific parameters are only extracted when rf_tech_specific_params_len is non-zero, so a notification that reports a zero length leaves the rf_tech_specific_params union uninitialised - and both handlers then pass it to nci_add_new_protocol(), which reads it: - discover: nci_add_new_target() -> nci_add_new_protocol(); - activated: nci_target_auto_activated() -> nci_add_new_protocol(). nci_add_new_protocol() uses nfca_poll->nfcid1_len as both a branch condition and a memcpy() length and copies nfcid1/sens_res/sel_res into ndev->targets, which is later exposed to user space via NFC_CMD_GET_TARGET. BUG: KMSAN: uninit-value in nci_add_new_protocol+0x624/0x6c0 nci_add_new_protocol+0x624/0x6c0 nci_ntf_packet+0x25b2/0x3c30 nci_rx_work+0x318/0x5d0 process_scheduled_works+0x84b/0x17a0 worker_thread+0xc10/0x11b0 kthread+0x376/0x500 Local variable ntf.i created at: nci_ntf_packet+0xbc2/0x3c30 Zero-initialise both on-stack notifications so the union reads back as zero when no technology-specific parameters are present. Fixes: 019c4fbaa790 ("NFC: Add NCI multiple targets support") Fixes: e8c0dacd9836 ("NFC: Update names and structs to NCI spec 1.0 d18") Link: https://lore.kernel.org/netdev/20260623172109.1105965-2-horms@kernel.org/ Cc: stable@vger.kernel.org Assisted-by: Bynario AI Signed-off-by: Samuel Page <sam@bynar.io> Link: https://patch.msgid.link/20260626090301.2139500-1-sam@bynar.io Signed-off-by: David Heidelberg <david@ixit.cz> 
nci_rf_discover_ntf_packet() and nci_rf_intf_activated_ntf_packet() each
parse a notification into an on-stack struct (nci_rf_discover_ntf /
nci_rf_intf_activated_ntf) that is not initialised. The RF
technology-specific parameters are only extracted when
rf_tech_specific_params_len is non-zero, so a notification that reports a
zero length leaves the rf_tech_specific_params union uninitialised - and
both handlers then pass it to nci_add_new_protocol(), which reads it:

 - discover:  nci_add_new_target() -> nci_add_new_protocol();
 - activated: nci_target_auto_activated() -> nci_add_new_protocol().

nci_add_new_protocol() uses nfca_poll->nfcid1_len as both a branch
condition and a memcpy() length and copies nfcid1/sens_res/sel_res into
ndev->targets, which is later exposed to user space via NFC_CMD_GET_TARGET.

  BUG: KMSAN: uninit-value in nci_add_new_protocol+0x624/0x6c0
   nci_add_new_protocol+0x624/0x6c0
   nci_ntf_packet+0x25b2/0x3c30
   nci_rx_work+0x318/0x5d0
   process_scheduled_works+0x84b/0x17a0
   worker_thread+0xc10/0x11b0
   kthread+0x376/0x500
  Local variable ntf.i created at:
   nci_ntf_packet+0xbc2/0x3c30

Zero-initialise both on-stack notifications so the union reads back as
zero when no technology-specific parameters are present.

Fixes: 019c4fbaa790 ("NFC: Add NCI multiple targets support")
Fixes: e8c0dacd9836 ("NFC: Update names and structs to NCI spec 1.0 d18")
Link: https://lore.kernel.org/netdev/20260623172109.1105965-2-horms@kernel.org/
Cc: stable@vger.kernel.org
Assisted-by: Bynario AI
Signed-off-by: Samuel Page <sam@bynar.io>
Link: https://patch.msgid.link/20260626090301.2139500-1-sam@bynar.io
Signed-off-by: David Heidelberg <david@ixit.cz>
nfc: nci: fix out-of-bounds write in nci_target_auto_activated() 2026-08-11T16:10:02+00:00 Samuel Page sam@bynar.io 2026-06-22T14:52:43+00:00 ac200079db50af81e6b04d058b33ec92901d8edd nci_target_auto_activated() appends a target to the fixed-size array ndev->targets[NCI_MAX_DISCOVERED_TARGETS] and increments ndev->n_targets without first checking the array is full; unlike its sibling nci_add_new_target(), which bails out when n_targets already equals NCI_MAX_DISCOVERED_TARGETS. ndev->n_targets is only cleared by nci_clear_target_list(), so an NFCC that repeatedly re-runs discovery (RF_DISCOVER_RSP, which re-enters NCI_DISCOVERY without clearing the target list) and reports an auto-activated target (RF_INTF_ACTIVATED_NTF) drives n_targets past the limit. The append then writes a struct nfc_target past the end of the array (a slab out-of-bounds write), and nfc_targets_found() goes on to walk the array with the inflated count: BUG: KASAN: slab-out-of-bounds in nci_add_new_protocol+0x94/0x2ac [nci] Write of size 2 at addr ffff0000c7299a18 by task kworker/u8:0/12 Workqueue: nfc0_nci_rx_wq nci_rx_work [nci] Call trace: nci_add_new_protocol+0x94/0x2ac [nci] nci_ntf_packet+0xddc/0x11a0 [nci] nci_rx_work+0x15c/0x1e0 [nci] process_one_work+0x2dc/0x500 worker_thread+0x240/0x460 kthread+0x1c0/0x1d0 ret_from_fork+0x10/0x20 The buggy address belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1024 bytes to the right of allocated 1560-byte region [ffff0000c7299000, ffff0000c7299618) Guard nci_target_auto_activated() with the same check used by nci_add_new_target(). Fixes: 019c4fbaa790 ("NFC: Add NCI multiple targets support") Cc: stable@vger.kernel.org Assisted-by: Bynario AI Signed-off-by: Samuel Page <sam@bynar.io> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20260622145243.3167276-1-sam@bynar.io Signed-off-by: David Heidelberg <david@ixit.cz> 
nci_target_auto_activated() appends a target to the fixed-size array
ndev->targets[NCI_MAX_DISCOVERED_TARGETS] and increments ndev->n_targets
without first checking the array is full; unlike its sibling
nci_add_new_target(), which bails out when n_targets already equals
NCI_MAX_DISCOVERED_TARGETS.

ndev->n_targets is only cleared by nci_clear_target_list(), so an NFCC
that repeatedly re-runs discovery (RF_DISCOVER_RSP, which re-enters
NCI_DISCOVERY without clearing the target list) and reports an
auto-activated target (RF_INTF_ACTIVATED_NTF) drives n_targets past the
limit. The append then writes a struct nfc_target past the end of the
array (a slab out-of-bounds write), and nfc_targets_found() goes on to
walk the array with the inflated count:

  BUG: KASAN: slab-out-of-bounds in nci_add_new_protocol+0x94/0x2ac [nci]
  Write of size 2 at addr ffff0000c7299a18 by task kworker/u8:0/12
  Workqueue: nfc0_nci_rx_wq nci_rx_work [nci]
  Call trace:
   nci_add_new_protocol+0x94/0x2ac [nci]
   nci_ntf_packet+0xddc/0x11a0 [nci]
   nci_rx_work+0x15c/0x1e0 [nci]
   process_one_work+0x2dc/0x500
   worker_thread+0x240/0x460
   kthread+0x1c0/0x1d0
   ret_from_fork+0x10/0x20

  The buggy address belongs to the cache kmalloc-2k of size 2048
  The buggy address is located 1024 bytes to the right of
  allocated 1560-byte region [ffff0000c7299000, ffff0000c7299618)

Guard nci_target_auto_activated() with the same check used by
nci_add_new_target().

Fixes: 019c4fbaa790 ("NFC: Add NCI multiple targets support")
Cc: stable@vger.kernel.org
Assisted-by: Bynario AI
Signed-off-by: Samuel Page <sam@bynar.io>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260622145243.3167276-1-sam@bynar.io
Signed-off-by: David Heidelberg <david@ixit.cz>
nfc: nci: add data_len bound checks to activation parameter extractors 2026-08-11T16:10:02+00:00 Bryam Vargas hexlabsecurity@proton.me 2026-06-12T17:50:25+00:00 0428fa2c22e2ba0cff766d3b80d461e149102045 nci_extract_activation_params_iso_dep() and nci_extract_activation_params_nfc_dep() read an inner length byte from the NCI RF_INTF_ACTIVATED_NTF payload and use it to memcpy() into fixed kernel buffers, but neither function receives the caller-validated activation_params_len. A crafted NCI notification with activation_params_len=1 and an inner length byte of up to 20 (NFC-A) or 50 (NFC-B) causes memcpy() to read that many bytes past the one valid byte in the activation params region -- a slab out-of-bounds read of kernel memory adjacent to the NCI skb. The sibling nci_extract_rf_params_*() family was given equivalent protection by commit 571dcbeb8e63 ("net: nfc: nci: Fix parameter validation for packet data"), but the two activation parameter extractors were not updated at that time. Add a data_len parameter to both functions, guard against an empty region before consuming the inner length byte, decrement the remaining count after consuming it, and clamp the copy length to what is actually available. Update both call sites to pass ntf.activation_params_len, which is already validated against the skb at ntf.c:801. Fixes: e8c0dacd9836 ("NFC: Update names and structs to NCI spec 1.0 d18") Cc: stable@vger.kernel.org Signed-off-by: Bryam Vargas <hexlabsecurity@proton.me> Link: https://patch.msgid.link/20260612-b4-disp-6d52d8b0-v3-1-e26221f8826d@proton.me Signed-off-by: David Heidelberg <david@ixit.cz> 
nci_extract_activation_params_iso_dep() and
nci_extract_activation_params_nfc_dep() read an inner length byte from
the NCI RF_INTF_ACTIVATED_NTF payload and use it to memcpy() into fixed
kernel buffers, but neither function receives the caller-validated
activation_params_len.  A crafted NCI notification with
activation_params_len=1 and an inner length byte of up to 20 (NFC-A) or
50 (NFC-B) causes memcpy() to read that many bytes past the one valid
byte in the activation params region -- a slab out-of-bounds read of
kernel memory adjacent to the NCI skb.

The sibling nci_extract_rf_params_*() family was given equivalent
protection by commit 571dcbeb8e63 ("net: nfc: nci: Fix parameter
validation for packet data"), but the two activation parameter
extractors were not updated at that time.

Add a data_len parameter to both functions, guard against an empty
region before consuming the inner length byte, decrement the remaining
count after consuming it, and clamp the copy length to what is actually
available.  Update both call sites to pass ntf.activation_params_len,
which is already validated against the skb at ntf.c:801.

Fixes: e8c0dacd9836 ("NFC: Update names and structs to NCI spec 1.0 d18")
Cc: stable@vger.kernel.org
Signed-off-by: Bryam Vargas <hexlabsecurity@proton.me>
Link: https://patch.msgid.link/20260612-b4-disp-6d52d8b0-v3-1-e26221f8826d@proton.me
Signed-off-by: David Heidelberg <david@ixit.cz>
nfc: nci: fix double completion race in nci_data_exchange_complete 2026-08-11T16:10:02+00:00 Zhenghang Xiao kipreyyy@gmail.com 2026-05-26T10:31:21+00:00 8265a626cc14a48e46e6dc8c47667e72b4232ac2 nci_close_device() and nci_rx_work can both call nci_data_exchange_complete() concurrently. After commit 4527025d440ce8 ("nfc: nci: fix circular locking dependency in nci_close_device") moved flush_workqueue(ndev->rx_wq) after mutex_unlock(&ndev->req_lock), rx_work is no longer serialized with the explicit completion call in the close path. Both callers read the non-NULL callback pointer and invoke rawsock_data_exchange_complete(), which calls sock_put() -- but only one sock_hold() was taken, so the second sock_put() underflows the refcount and frees the socket while it is still in use. Replace the bare clear_bit(NCI_DATA_EXCHANGE) with test_and_clear_bit() so that only the first caller proceeds to invoke the callback. Fixes: 4527025d440c ("nfc: nci: fix circular locking dependency in nci_close_device") Signed-off-by: Zhenghang Xiao <kipreyyy@gmail.com> Link: https://patch.msgid.link/20260526103121.47957-1-kipreyyy@gmail.com Signed-off-by: David Heidelberg <david@ixit.cz> 
nci_close_device() and nci_rx_work can both call
nci_data_exchange_complete() concurrently.  After commit 4527025d440ce8
("nfc: nci: fix circular locking dependency in nci_close_device") moved
flush_workqueue(ndev->rx_wq) after mutex_unlock(&ndev->req_lock),
rx_work is no longer serialized with the explicit completion call in the
close path.  Both callers read the non-NULL callback pointer and invoke
rawsock_data_exchange_complete(), which calls sock_put() -- but only one
sock_hold() was taken, so the second sock_put() underflows the refcount
and frees the socket while it is still in use.

Replace the bare clear_bit(NCI_DATA_EXCHANGE) with
test_and_clear_bit() so that only the first caller proceeds to invoke
the callback.

Fixes: 4527025d440c ("nfc: nci: fix circular locking dependency in nci_close_device")
Signed-off-by: Zhenghang Xiao <kipreyyy@gmail.com>
Link: https://patch.msgid.link/20260526103121.47957-1-kipreyyy@gmail.com
Signed-off-by: David Heidelberg <david@ixit.cz>
nfc: nci: uart: Constify struct tty_ldisc_ops 2026-06-11T18:21:32+00:00 Christophe JAILLET christophe.jaillet@wanadoo.fr 2026-05-10T20:12:52+00:00 5251ffc72996ed9e447ca637db80141627476b09 'struct tty_ldisc_ops' is not modified in this driver. Constifying this structure moves some data to a read-only section, so increases overall security, especially when the structure holds some function pointers. On a x86_64, with allmodconfig: Before: ====== text data bss dec hex filename 11454 3352 256 15062 3ad6 net/nfc/nci/uart.o After: ===== text data bss dec hex filename 11646 3160 256 15062 3ad6 net/nfc/nci/uart.o Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Link: https://patch.msgid.link/c756755a72cdfde2877a18ddee01eaa4f633c220.1778443960.git.christophe.jaillet@wanadoo.fr Signed-off-by: David Heidelberg <david@ixit.cz> 
'struct tty_ldisc_ops' is not modified in this driver.

Constifying this structure moves some data to a read-only section, so
increases overall security, especially when the structure holds some
function pointers.

On a x86_64, with allmodconfig:
Before:
======
   text	   data	    bss	    dec	    hex	filename
  11454	   3352	    256	  15062	   3ad6	net/nfc/nci/uart.o

After:
=====
   text	   data	    bss	    dec	    hex	filename
  11646	   3160	    256	  15062	   3ad6	net/nfc/nci/uart.o

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://patch.msgid.link/c756755a72cdfde2877a18ddee01eaa4f633c220.1778443960.git.christophe.jaillet@wanadoo.fr
Signed-off-by: David Heidelberg <david@ixit.cz>
nfc: hci: fix out-of-bounds read in HCP header parsing 2026-05-07T10:42:09+00:00 Ashutosh Desai ashutoshdesai993@gmail.com 2026-05-05T17:07:12+00:00 f040e590c035bfd9553fe79ee9585caf1b14d67b Both nfc_hci_recv_from_llc() and nci_hci_data_received_cb() read packet->header from skb->data at function entry without first checking that the buffer holds at least one byte. A malicious NFC peer can send a 0-byte HCP frame that passes through the SHDLC layer and reaches these functions, causing an out-of-bounds heap read of packet->header. The same 0-byte frame, if queued as a non-final fragment, also causes the reassembly loop to underflow msg_len to UINT_MAX, triggering skb_over_panic() when the reassembled skb is written. Fix this by adding a pskb_may_pull() check at the entry of each function before packet->header is first accessed. The existing pskb_may_pull() checks before the reassembled hcp_skb is cast to struct hcp_packet remain in place to guard the 2-byte HCP message header. Fixes: 8b8d2e08bf0d ("NFC: HCI support") Fixes: 11f54f228643 ("NFC: nci: Add HCI over NCI protocol support") Cc: stable@vger.kernel.org Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Ashutosh Desai <ashutoshdesai993@gmail.com> Link: https://patch.msgid.link/20260505170712.96560-1-ashutoshdesai993@gmail.com Signed-off-by: David Heidelberg <david@ixit.cz> 
Both nfc_hci_recv_from_llc() and nci_hci_data_received_cb() read
packet->header from skb->data at function entry without first checking
that the buffer holds at least one byte. A malicious NFC peer can send
a 0-byte HCP frame that passes through the SHDLC layer and reaches
these functions, causing an out-of-bounds heap read of packet->header.
The same 0-byte frame, if queued as a non-final fragment, also causes
the reassembly loop to underflow msg_len to UINT_MAX, triggering
skb_over_panic() when the reassembled skb is written.

Fix this by adding a pskb_may_pull() check at the entry of each
function before packet->header is first accessed. The existing
pskb_may_pull() checks before the reassembled hcp_skb is cast to
struct hcp_packet remain in place to guard the 2-byte HCP message
header.

Fixes: 8b8d2e08bf0d ("NFC: HCI support")
Fixes: 11f54f228643 ("NFC: nci: Add HCI over NCI protocol support")
Cc: stable@vger.kernel.org
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Ashutosh Desai <ashutoshdesai993@gmail.com>
Link: https://patch.msgid.link/20260505170712.96560-1-ashutoshdesai993@gmail.com
Signed-off-by: David Heidelberg <david@ixit.cz>
nfc: nci: fix circular locking dependency in nci_close_device 2026-03-19T23:56:18+00:00 Jakub Kicinski kuba@kernel.org 2026-03-17T19:33:34+00:00 4527025d440ce84bf56e75ce1df2e84cb8178616 nci_close_device() flushes rx_wq and tx_wq while holding req_lock. This causes a circular locking dependency because nci_rx_work() running on rx_wq can end up taking req_lock too: nci_rx_work -> nci_rx_data_packet -> nci_data_exchange_complete -> __sk_destruct -> rawsock_destruct -> nfc_deactivate_target -> nci_deactivate_target -> nci_request -> mutex_lock(&ndev->req_lock) Move the flush of rx_wq after req_lock has been released. This should safe (I think) because NCI_UP has already been cleared and the transport is closed, so the work will see it and return -ENETDOWN. NIPA has been hitting this running the nci selftest with a debug kernel on roughly 4% of the runs. Fixes: 6a2968aaf50c ("NFC: basic NCI protocol implementation") Reviewed-by: Ian Ray <ian.ray@gehealthcare.com> Link: https://patch.msgid.link/20260317193334.988609-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
nci_close_device() flushes rx_wq and tx_wq while holding req_lock.
This causes a circular locking dependency because nci_rx_work()
running on rx_wq can end up taking req_lock too:

  nci_rx_work -> nci_rx_data_packet -> nci_data_exchange_complete
    -> __sk_destruct -> rawsock_destruct -> nfc_deactivate_target
    -> nci_deactivate_target -> nci_request -> mutex_lock(&ndev->req_lock)

Move the flush of rx_wq after req_lock has been released.
This should safe (I think) because NCI_UP has already been cleared
and the transport is closed, so the work will see it and return
-ENETDOWN.

NIPA has been hitting this running the nci selftest with a debug
kernel on roughly 4% of the runs.

Fixes: 6a2968aaf50c ("NFC: basic NCI protocol implementation")
Reviewed-by: Ian Ray <ian.ray@gehealthcare.com>
Link: https://patch.msgid.link/20260317193334.988609-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>