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7ce9bb0b95
[ Upstream commit 2935e556850e9c94d7a00adf14d3cd7fe406ac03 ]
Function 'hci_discovery_filter_clear()' frees 'uuids' array and then
sets it to NULL. There is a tiny chance of the following race:
'hci_cmd_sync_work()'
'update_passive_scan_sync()'
'hci_update_passive_scan_sync()'
'hci_discovery_filter_clear()'
kfree(uuids);
<-------------------------preempted-------------------------------->
'start_service_discovery()'
'hci_discovery_filter_clear()'
kfree(uuids); // DOUBLE FREE
<-------------------------preempted-------------------------------->
uuids = NULL;
To fix it let's add locking around 'kfree()' call and NULL pointer
assignment. Otherwise the following backtrace fires:
[ ] ------------[ cut here ]------------
[ ] kernel BUG at mm/slub.c:547!
[ ] Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
[ ] CPU: 3 UID: 0 PID: 246 Comm: bluetoothd Tainted: G O 6.12.19-kernel #1
[ ] Tainted: [O]=OOT_MODULE
[ ] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ ] pc : __slab_free+0xf8/0x348
[ ] lr : __slab_free+0x48/0x348
...
[ ] Call trace:
[ ] __slab_free+0xf8/0x348
[ ] kfree+0x164/0x27c
[ ] start_service_discovery+0x1d0/0x2c0
[ ] hci_sock_sendmsg+0x518/0x924
[ ] __sock_sendmsg+0x54/0x60
[ ] sock_write_iter+0x98/0xf8
[ ] do_iter_readv_writev+0xe4/0x1c8
[ ] vfs_writev+0x128/0x2b0
[ ] do_writev+0xfc/0x118
[ ] __arm64_sys_writev+0x20/0x2c
[ ] invoke_syscall+0x68/0xf0
[ ] el0_svc_common.constprop.0+0x40/0xe0
[ ] do_el0_svc+0x1c/0x28
[ ] el0_svc+0x30/0xd0
[ ] el0t_64_sync_handler+0x100/0x12c
[ ] el0t_64_sync+0x194/0x198
[ ] Code: 8b0002e6 eb17031f 54fffbe1 d503201f (d4210000)
[ ] ---[ end trace 0000000000000000 ]---
Fixes: ad383c2c65 ("Bluetooth: hci_sync: Enable advertising when LL privacy is enabled")
Signed-off-by: Arseniy Krasnov <avkrasnov@salutedevices.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
[ Minor context change fixed. ]
Signed-off-by: Alva Lan <alvalan9@foxmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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.