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Hawkins Jiawei aa16cac06b Bluetooth: L2CAP: Fix memory leak in vhci_write
[ Upstream commit 7c9524d929 ]

Syzkaller reports a memory leak as follows:
====================================
BUG: memory leak
unreferenced object 0xffff88810d81ac00 (size 240):
  [...]
  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:
    [<ffffffff838733d9>] __alloc_skb+0x1f9/0x270 net/core/skbuff.c:418
    [<ffffffff833f742f>] alloc_skb include/linux/skbuff.h:1257 [inline]
    [<ffffffff833f742f>] bt_skb_alloc include/net/bluetooth/bluetooth.h:469 [inline]
    [<ffffffff833f742f>] vhci_get_user drivers/bluetooth/hci_vhci.c:391 [inline]
    [<ffffffff833f742f>] vhci_write+0x5f/0x230 drivers/bluetooth/hci_vhci.c:511
    [<ffffffff815e398d>] call_write_iter include/linux/fs.h:2192 [inline]
    [<ffffffff815e398d>] new_sync_write fs/read_write.c:491 [inline]
    [<ffffffff815e398d>] vfs_write+0x42d/0x540 fs/read_write.c:578
    [<ffffffff815e3cdd>] ksys_write+0x9d/0x160 fs/read_write.c:631
    [<ffffffff845e0645>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
    [<ffffffff845e0645>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
    [<ffffffff84600087>] entry_SYSCALL_64_after_hwframe+0x63/0xcd
====================================

HCI core will uses hci_rx_work() to process frame, which is queued to
the hdev->rx_q tail in hci_recv_frame() by HCI driver.

Yet the problem is that, HCI core may not free the skb after handling
ACL data packets. To be more specific, when start fragment does not
contain the L2CAP length, HCI core just copies skb into conn->rx_skb and
finishes frame process in l2cap_recv_acldata(), without freeing the skb,
which triggers the above memory leak.

This patch solves it by releasing the relative skb, after processing
the above case in l2cap_recv_acldata().

Fixes: 4d7ea8ee90 ("Bluetooth: L2CAP: Fix handling fragmented length")
Link: https://lore.kernel.org/all/0000000000000d0b1905e6aaef64@google.com/
Reported-and-tested-by: syzbot+8f819e36e01022991cfa@syzkaller.appspotmail.com
Signed-off-by: Hawkins Jiawei <yin31149@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-10 18:15:30 +01:00
arch KVM: x86: Add compat handler for KVM_X86_SET_MSR_FILTER 2022-11-10 18:15:25 +01:00
block blk-wbt: fix that 'rwb->wc' is always set to 1 in wbt_init() 2022-10-26 12:35:54 +02:00
certs certs/blacklist_hashes.c: fix const confusion in certs blacklist 2022-06-22 14:22:01 +02:00
crypto crypto: akcipher - default implementation for setting a private key 2022-10-26 12:35:25 +02:00
Documentation arm64: errata: Remove AES hwcap for COMPAT tasks 2022-10-29 10:12:53 +02:00
drivers Bluetooth: virtio_bt: Use skb_put to set length 2022-11-10 18:15:30 +01:00
fs btrfs: fix ulist leaks in error paths of qgroup self tests 2022-11-10 18:15:30 +01:00
include mm/hugetlb: fix races when looking up a CONT-PTE/PMD size hugetlb page 2022-11-10 18:15:24 +01:00
init stack: Declare {randomize_,}kstack_offset to fix Sparse warnings 2022-08-17 14:23:10 +02:00
ipc ipc/mqueue: use get_tree_nodev() in mqueue_get_tree() 2022-06-09 10:23:10 +02:00
kernel PM: hibernate: Allow hybrid sleep to work with s2idle 2022-11-03 23:59:17 +09:00
lib lib/Kconfig.debug: Add check for non-constant .{s,u}leb128 support to DWARF5 2022-10-26 12:35:55 +02:00
LICENSES LICENSES/dual/CC-BY-4.0: Git rid of "smart quotes" 2021-07-15 06:31:24 -06:00
mm mm/hugetlb: fix races when looking up a CONT-PTE/PMD size hugetlb page 2022-11-10 18:15:24 +01:00
net Bluetooth: L2CAP: Fix memory leak in vhci_write 2022-11-10 18:15:30 +01:00
samples samples/landlock: Format with clang-format 2022-06-09 10:23:23 +02:00
scripts kbuild: rpm-pkg: fix breakage when V=1 is used 2022-10-26 12:35:27 +02:00
security selinux: enable use of both GFP_KERNEL and GFP_ATOMIC in convert_context() 2022-10-29 10:12:54 +02:00
sound ALSA: aoa: Fix I2S device accounting 2022-11-03 23:59:18 +09:00
tools perf vendor events arm64: Fix incorrect Hisi hip08 L3 metrics 2022-11-03 23:59:18 +09:00
usr usr/include/Makefile: add linux/nfc.h to the compile-test coverage 2022-02-01 17:27:15 +01:00
virt kvm: Add support for arch compat vm ioctls 2022-10-29 10:12:54 +02:00
.clang-format clang-format: Update with the latest for_each macro list 2021-05-12 23:32:39 +02:00
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.mailmap mailmap: add Andrej Shadura 2021-10-18 20:22:03 -10:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Daniel Drake to credits 2021-09-21 08:34:58 +03:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Input: goodix - add a goodix.h header file 2022-07-12 16:34:51 +02:00
Makefile Linux 5.15.77 2022-11-03 23:59:20 +09:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.