Deepak Sharma c395d1e548 net: nfc: nci: Add parameter validation for packet data ... commit 9c328f5474 upstream. Syzbot reported an uninitialized value bug in nci_init_req, which was introduced by commit 5aca7966d2 ("Merge tag 'perf-tools-fixes-for-v6.17-2025-09-16' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools"). This bug arises due to very limited and poor input validation that was done at nic_valid_size(). This validation only validates the skb->len (directly reflects size provided at the userspace interface) with the length provided in the buffer itself (interpreted as NCI_HEADER). This leads to the processing of memory content at the address assuming the correct layout per what opcode requires there. This leads to the accesses to buffer of `skb_buff->data` which is not assigned anything yet. Following the same silent drop of packets of invalid sizes at `nic_valid_size()`, add validation of the data in the respective handlers and return error values in case of failure. Release the skb if error values are returned from handlers in `nci_nft_packet` and effectively do a silent drop Possible TODO: because we silently drop the packets, the call to `nci_request` will be waiting for completion of request and will face timeouts. These timeouts can get excessively logged in the dmesg. A proper handling of them may require to export `nci_request_cancel` (or propagate error handling from the nft packets handlers). Reported-by: syzbot+740e04c2a93467a0f8c8@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=740e04c2a93467a0f8c8 Fixes: 6a2968aaf5 ("NFC: basic NCI protocol implementation") Tested-by: syzbot+740e04c2a93467a0f8c8@syzkaller.appspotmail.com Cc: stable@vger.kernel.org Signed-off-by: Deepak Sharma <deepak.sharma.472935@gmail.com> Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev> Link: https://patch.msgid.link/20250925132846.213425-1-deepak.sharma.472935@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2025-10-15 12:04:16 +02:00
..
core.c	treewide, timers: Rename from_timer() to timer_container_of()	2025-06-08 09:07:37 +02:00
data.c	treewide: Switch/rename to timer_delete[_sync]()	2025-04-05 10:30:12 +02:00
hci.c
Kconfig
lib.c
Makefile
ntf.c	net: nfc: nci: Add parameter validation for packet data	2025-10-15 12:04:16 +02:00
rsp.c	treewide: Switch/rename to timer_delete[_sync]()	2025-04-05 10:30:12 +02:00
spi.c
uart.c	NFC: nci: uart: Set tty->disc_data only in success path	2025-06-19 08:33:54 -07:00