diff options
| author | Wang Liang <wangliang74@huawei.com> | 2025-08-30 15:50:23 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-10-15 11:57:59 +0200 |
| commit | cf71834a0cfc394c72d62fd6dbb470ee13cf8f5e (patch) | |
| tree | 408d2040e2115b3ac4f0768cc6a0ea486cdb0703 /drivers/pps/kapi.c | |
| parent | b859d612303a9398b0ca11ae2c8cec81aef189c4 (diff) | |
pps: fix warning in pps_register_cdev when register device fail
[ Upstream commit b0531cdba5029f897da5156815e3bdafe1e9b88d ]
Similar to previous commit 2a934fdb01db ("media: v4l2-dev: fix error
handling in __video_register_device()"), the release hook should be set
before device_register(). Otherwise, when device_register() return error
and put_device() try to callback the release function, the below warning
may happen.
------------[ cut here ]------------
WARNING: CPU: 1 PID: 4760 at drivers/base/core.c:2567 device_release+0x1bd/0x240 drivers/base/core.c:2567
Modules linked in:
CPU: 1 UID: 0 PID: 4760 Comm: syz.4.914 Not tainted 6.17.0-rc3+ #1 NONE
RIP: 0010:device_release+0x1bd/0x240 drivers/base/core.c:2567
Call Trace:
<TASK>
kobject_cleanup+0x136/0x410 lib/kobject.c:689
kobject_release lib/kobject.c:720 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0xe9/0x130 lib/kobject.c:737
put_device+0x24/0x30 drivers/base/core.c:3797
pps_register_cdev+0x2da/0x370 drivers/pps/pps.c:402
pps_register_source+0x2f6/0x480 drivers/pps/kapi.c:108
pps_tty_open+0x190/0x310 drivers/pps/clients/pps-ldisc.c:57
tty_ldisc_open+0xa7/0x120 drivers/tty/tty_ldisc.c:432
tty_set_ldisc+0x333/0x780 drivers/tty/tty_ldisc.c:563
tiocsetd drivers/tty/tty_io.c:2429 [inline]
tty_ioctl+0x5d1/0x1700 drivers/tty/tty_io.c:2728
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:598 [inline]
__se_sys_ioctl fs/ioctl.c:584 [inline]
__x64_sys_ioctl+0x194/0x210 fs/ioctl.c:584
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x5f/0x2a0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
</TASK>
Before commit c79a39dc8d06 ("pps: Fix a use-after-free"),
pps_register_cdev() call device_create() to create pps->dev, which will
init dev->release to device_create_release(). Now the comment is outdated,
just remove it.
Thanks for the reminder from Calvin Owens, 'kfree_pps' should be removed
in pps_register_source() to avoid a double free in the failure case.
Link: https://lore.kernel.org/all/20250827065010.3208525-1-wangliang74@huawei.com/
Fixes: c79a39dc8d06 ("pps: Fix a use-after-free")
Signed-off-by: Wang Liang <wangliang74@huawei.com>
Reviewed-By: Calvin Owens <calvin@wbinvd.org>
Link: https://lore.kernel.org/r/20250830075023.3498174-1-wangliang74@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/pps/kapi.c')
| -rw-r--r-- | drivers/pps/kapi.c | 5 |
1 files changed, 1 insertions, 4 deletions
diff --git a/drivers/pps/kapi.c b/drivers/pps/kapi.c index 92d1b62ea239..e9389876229e 100644 --- a/drivers/pps/kapi.c +++ b/drivers/pps/kapi.c @@ -109,16 +109,13 @@ struct pps_device *pps_register_source(struct pps_source_info *info, if (err < 0) { pr_err("%s: unable to create char device\n", info->name); - goto kfree_pps; + goto pps_register_source_exit; } dev_dbg(&pps->dev, "new PPS source %s\n", info->name); return pps; -kfree_pps: - kfree(pps); - pps_register_source_exit: pr_err("%s: unable to register source\n", info->name); |