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  1. 29 Dec, 2023 1 commit
  3. 27 Dec, 2023 1 commit
  5. 26 Dec, 2023 1 commit
  7. 25 Dec, 2023 3 commits
    • David S. Miller's avatar
      Merge branch 'nfc-refcounting' · dff90e4a
      David S. Miller authored 
      @ 2023-12-19 17:49 Siddh Raman Pant
  2023-12-19 17:49 ` [PATCH net-next v7 1/2] nfc: llcp_core: Hold a ref to llcp_local->dev when holding a ref to llcp_local Siddh Raman Pant
  2023-12-19 17:49 ` [PATCH net-next v7 2/2] nfc: Do not send datagram if socket state isn't LLCP_BOUND Siddh Raman Pant
  0 siblings, 2 replies; 4+ messages in thread
Siddh Raman Pant says:

====================
[PATCH net-next v7 0/2] nfc: Fix UAF during datagram sending caused by missing refcounting

Changes in v7:
- Stupidly reverted ordering in recv() too, fix that.
- Remove redundant call to nfc_llcp_sock_free().

Changes in v6:
- Revert label introduction from v4, and thus also v5 entirely.

Changes in v5:
- Move reason = LLCP_DM_REJ under the fail_put_sock label.
- Checkpatch now warns about == NULL check for new_sk, so fix that,
  and also at other similar places in the same function.

Changes in v4:
- Fix put ordering and comments.
- Separate freeing in recv() into end labels.
- Remove obvious comment and add reasoning.
- Picked up r-bs by Suman.

Changes in v3:
- Fix missing freeing statements.

Changes in v2:
- Add net-next in patch subject.
- Removed unnecessary extra lock and hold nfc_dev ref when holding llcp_sock.
- Remove last formatting patch.
- Picked up r-b from Krzysztof for LLCP_BOUND patch.

---

For connectionless transmission, llcp_sock_sendmsg() codepath will
eventually call nfc_alloc_send_skb() which takes in an nfc_dev as
an argument for calculating the total size for skb allocation.

virtual_ncidev_close() codepath eventually releases socket by calling
nfc_llcp_socket_release() (which sets the sk->sk_state to LLCP_CLOSED)
and afterwards the nfc_dev will be eventually freed.

When an ndev gets freed, llcp_sock_sendmsg() will result in an
use-after-free as it

(1) doesn't have any checks in place for avoiding the datagram sending.

(2) calls nfc_llcp_send_ui_frame(), which also has a do-while loop
    which can race with freeing. This loop contains the call to
    nfc_alloc_send_skb() where we dereference the nfc_dev pointer.

nfc_dev is being freed because we do not hold a reference to it when
we hold a reference to llcp_local. Thus, virtual_ncidev_close()
eventually calls nfc_release() due to refcount going to 0.

Since state has to be LLCP_BOUND for datagram sending, we can bail out
early in llcp_sock_sendmsg().

Please review and let me know if any errors are there, and hopefully
this gets accepted.
====================
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      dff90e4a
    • Siddh Raman Pant's avatar
      nfc: Do not send datagram if socket state isn't LLCP_BOUND · 6ec0d752
      Siddh Raman Pant authored 
      As we know we cannot send the datagram (state can be set to LLCP_CLOSED
by nfc_llcp_socket_release()), there is no need to proceed further.

Thus, bail out early from llcp_sock_sendmsg().
Signed-off-by: default avatarSiddh Raman Pant <code@siddh.me>
Reviewed-by: default avatarKrzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: default avatarSuman Ghosh <sumang@marvell.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      6ec0d752
    • Siddh Raman Pant's avatar
      nfc: llcp_core: Hold a ref to llcp_local->dev when holding a ref to llcp_local · c95f9195
      Siddh Raman Pant authored 
      llcp_sock_sendmsg() calls nfc_llcp_send_ui_frame() which in turn calls
nfc_alloc_send_skb(), which accesses the nfc_dev from the llcp_sock for
getting the headroom and tailroom needed for skb allocation.

Parallelly the nfc_dev can be freed, as the refcount is decreased via
nfc_free_device(), leading to a UAF reported by Syzkaller, which can
be summarized as follows:

(1) llcp_sock_sendmsg() -> nfc_llcp_send_ui_frame()
	-> nfc_alloc_send_skb() -> Dereference *nfc_dev
(2) virtual_ncidev_close() -> nci_free_device() -> nfc_free_device()
	-> put_device() -> nfc_release() -> Free *nfc_dev

When a reference to llcp_local is acquired, we do not acquire the same
for the nfc_dev. This leads to freeing even when the llcp_local is in
use, and this is the case with the UAF described above too.

Thus, when we acquire a reference to llcp_local, we should acquire a
reference to nfc_dev, and release the references appropriately later.

References for llcp_local is initialized in nfc_llcp_register_device()
(which is called by nfc_register_device()). Thus, we should acquire a
reference to nfc_dev there.

nfc_unregister_device() calls nfc_llcp_unregister_device() which in
turn calls nfc_llcp_local_put(). Thus, the reference to nfc_dev is
appropriately released later.

Reported-and-tested-by: syzbot+bbe84a4010eeea00982d@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=bbe84a4010eeea00982d
Fixes: c7aa1225 ("NFC: Take a reference on the LLCP local pointer when creating a socket")
Reviewed-by: default avatarSuman Ghosh <sumang@marvell.com>
Signed-off-by: default avatarSiddh Raman Pant <code@siddh.me>
Reviewed-by: default avatarKrzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      c95f9195
  9. 21 Dec, 2023 12 commits
  11. 20 Dec, 2023 13 commits
  13. 19 Dec, 2023 9 commits
    • Kent Overstreet's avatar
      bcachefs; guard against overflow in btree node split · 7ba1f6ec
      Kent Overstreet authored 
      Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
      7ba1f6ec
    • Kent Overstreet's avatar
      bcachefs: btree_node_u64s_with_format() takes nr keys · 0fa3b977
      Kent Overstreet authored 
      Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
      0fa3b977
    • Linus Torvalds's avatar
      Merge tag 'trace-v6.7-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace · 55cb5f43
      Linus Torvalds authored 
      Pull tracing fix from Steven Rostedt:
 "While working on the ring buffer, I found one more bug with the
  timestamp code, and the fix for this removed the need for the final
  64-bit cmpxchg!

  The ring buffer events hold a "delta" from the previous event. If it
  is determined that the delta can not be calculated, it falls back to
  adding an absolute timestamp value. The way to know if the delta can
  be used is via two stored timestamps in the per-cpu buffer meta data:

   before_stamp and write_stamp

  The before_stamp is written by every event before it tries to allocate
  its space on the ring buffer. The write_stamp is written after it
  allocates its space and knows that nothing came in after it read the
  previous before_stamp and write_stamp and the two matched.

  A previous fix dd939425 ("ring-buffer: Do not try to put back
  write_stamp") removed putting back the write_stamp to match the
  before_stamp so that the next event could use the delta, but races
  were found where the two would match, but not be for of the previous
  event.

  It was determined to allow the event reservation to not have a valid
  write_stamp when it is finished, and this fixed a lot of races.

  The last use of the 64-bit timestamp cmpxchg depended on the
  write_stamp being valid after an interruption. But this is no longer
  the case, as if an event is interrupted by a softirq that writes an
  event, and that event gets interrupted by a hardirq or NMI and that
  writes an event, then the softirq could finish its reservation without
  a valid write_stamp.

  In the slow path of the event reservation, a delta can still be used
  if the write_stamp is valid. Instead of using a cmpxchg against the
  write stamp, the before_stamp needs to be read again to validate the
  write_stamp. The cmpxchg is not needed.

  This updates the slowpath to validate the write_stamp by comparing it
  to the before_stamp and removes all rb_time_cmpxchg() as there are no
  more users of that function.

  The removal of the 32-bit updates of rb_time_t will be done in the
  next merge window"

* tag 'trace-v6.7-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Fix slowpath of interrupted event
      55cb5f43
    • Linus Torvalds's avatar
      Merge tag 'arc-6.7-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc · 9c749e61
      Linus Torvalds authored 
      Pull ARC fixes from Vineet Gupta:

 - build error for hugetlb, sparse and smatch fixes

 - removal of VIPT aliasing cache code

* tag 'arc-6.7-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: add hugetlb definitions
  ARC: fix smatch warning
  ARC: fix spare error
  ARC: mm: retire support for aliasing VIPT D$
  ARC: entry: move ARCompact specific bits out of entry.h
  ARC: entry: SAVE_ABI_CALLEE_REG: ISA/ABI specific helper
      9c749e61
    • Shyam Prasad N's avatar
      cifs: do not let cifs_chan_update_iface deallocate channels · 12d1e301
      Shyam Prasad N authored 
      cifs_chan_update_iface is meant to check and update the server
interface used for a channel when the existing server interface
is no longer available.

So far, this handler had the code to remove an interface entry
even if a new candidate interface is not available. Allowing
this leads to several corner cases to handle.

This change makes the logic much simpler by not deallocating
the current channel interface entry if a new interface is not
found to replace it with.
Signed-off-by: default avatarShyam Prasad N <sprasad@microsoft.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
      12d1e301
    • Shyam Prasad N's avatar
      cifs: fix a pending undercount of srv_count · f30bbc38
      Shyam Prasad N authored 
      The following commit reverted the changes to ref count
the server struct while scheduling a reconnect work:
82334252 Revert "cifs: reconnect work should have reference on server struct"

However, a following change also introduced scheduling
of reconnect work, and assumed ref counting. This change
fixes that as well.

Fixes umount problems like:

[73496.157838] CPU: 5 PID: 1321389 Comm: umount Tainted: G        W  OE      6.7.0-060700rc6-generic #202312172332
[73496.157841] Hardware name: LENOVO 20MAS08500/20MAS08500, BIOS N2CET67W (1.50 ) 12/15/2022
[73496.157843] RIP: 0010:cifs_put_tcp_session+0x17d/0x190 [cifs]
[73496.157906] Code: 5d 31 c0 31 d2 31 f6 31 ff c3 cc cc cc cc e8 4a 6e 14 e6 e9 f6 fe ff ff be 03 00 00 00 48 89 d7 e8 78 26 b3 e5 e9 e4 fe ff ff <0f> 0b e9 b1 fe ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90
[73496.157908] RSP: 0018:ffffc90003bcbcb8 EFLAGS: 00010286
[73496.157911] RAX: 00000000ffffffff RBX: ffff8885830fa800 RCX: 0000000000000000
[73496.157913] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[73496.157915] RBP: ffffc90003bcbcc8 R08: 0000000000000000 R09: 0000000000000000
[73496.157917] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[73496.157918] R13: ffff8887d56ba800 R14: 00000000ffffffff R15: ffff8885830fa800
[73496.157920] FS:  00007f1ff0e33800(0000) GS:ffff88887ba80000(0000) knlGS:0000000000000000
[73496.157922] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[73496.157924] CR2: 0000115f002e2010 CR3: 00000003d1e24005 CR4: 00000000003706f0
[73496.157926] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[73496.157928] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[73496.157929] Call Trace:
[73496.157931]  <TASK>
[73496.157933]  ? show_regs+0x6d/0x80
[73496.157936]  ? __warn+0x89/0x160
[73496.157939]  ? cifs_put_tcp_session+0x17d/0x190 [cifs]
[73496.157976]  ? report_bug+0x17e/0x1b0
[73496.157980]  ? handle_bug+0x51/0xa0
[73496.157983]  ? exc_invalid_op+0x18/0x80
[73496.157985]  ? asm_exc_invalid_op+0x1b/0x20
[73496.157989]  ? cifs_put_tcp_session+0x17d/0x190 [cifs]
[73496.158023]  ? cifs_put_tcp_session+0x1e/0x190 [cifs]
[73496.158057]  __cifs_put_smb_ses+0x2b5/0x540 [cifs]
[73496.158090]  ? tconInfoFree+0xc2/0x120 [cifs]
[73496.158130]  cifs_put_tcon.part.0+0x108/0x2b0 [cifs]
[73496.158173]  cifs_put_tlink+0x49/0x90 [cifs]
[73496.158220]  cifs_umount+0x56/0xb0 [cifs]
[73496.158258]  cifs_kill_sb+0x52/0x60 [cifs]
[73496.158306]  deactivate_locked_super+0x32/0xc0
[73496.158309]  deactivate_super+0x46/0x60
[73496.158311]  cleanup_mnt+0xc3/0x170
[73496.158314]  __cleanup_mnt+0x12/0x20
[73496.158330]  task_work_run+0x5e/0xa0
[73496.158333]  exit_to_user_mode_loop+0x105/0x130
[73496.158336]  exit_to_user_mode_prepare+0xa5/0xb0
[73496.158338]  syscall_exit_to_user_mode+0x29/0x60
[73496.158341]  do_syscall_64+0x6c/0xf0
[73496.158344]  ? syscall_exit_to_user_mode+0x37/0x60
[73496.158346]  ? do_syscall_64+0x6c/0xf0
[73496.158349]  ? exit_to_user_mode_prepare+0x30/0xb0
[73496.158353]  ? syscall_exit_to_user_mode+0x37/0x60
[73496.158355]  ? do_syscall_64+0x6c/0xf0
Reported-by: default avatarRobert Morris <rtm@csail.mit.edu>
Fixes: 705fc522 ("cifs: handle when server starts supporting multichannel")
Signed-off-by: default avatarShyam Prasad N <sprasad@microsoft.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
      f30bbc38
    • Heiko Carstens's avatar
      s390: update defconfigs · 3d940bb1
      Heiko Carstens authored 
      Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
      3d940bb1
    • Zizhi Wo's avatar
      fs: cifs: Fix atime update check · 01fe654f
      Zizhi Wo authored 
      Commit 9b9c5bea ("cifs: do not return atime less than mtime") indicates
that in cifs, if atime is less than mtime, some apps will break.
Therefore, it introduce a function to compare this two variables in two
places where atime is updated. If atime is less than mtime, update it to
mtime.

However, the patch was handled incorrectly, resulting in atime and mtime
being exactly equal. A previous commit 69738cfd ("fs: cifs: Fix atime
update check vs mtime") fixed one place and forgot to fix another. Fix it.

Fixes: 9b9c5bea ("cifs: do not return atime less than mtime")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarZizhi Wo <wozizhi@huawei.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
      01fe654f
    • Paulo Alcantara's avatar
      smb: client: fix potential OOB in smb2_dump_detail() · 567320c4
      Paulo Alcantara authored 
      Validate SMB message with ->check_message() before calling
->calc_smb_size().

This fixes CVE-2023-6610.

Reported-by: j51569436@gmail.com
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218219
Cc; stable@vger.kernel.org
Signed-off-by: default avatarPaulo Alcantara <pc@manguebit.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
      567320c4
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