kernel/drivers/base, branch linux-5.7.y

driver core: Avoid binding drivers to dead devices

2020-08-21T11:07:26Z

commit 654888327e9f655a9d55ad477a9583e90e8c9b5c upstream. Commit 3451a495ef24 ("driver core: Establish order of operations for device_add and device_del via bitflag") sought to prevent asynchronous driver binding to a device which is being removed. It added a per-device "dead" flag which is checked in the following code paths: * asynchronous binding in __driver_attach_async_helper() * synchronous binding in device_driver_attach() * asynchronous binding in __device_attach_async_helper() It did *not* check the flag upon: * synchronous binding in __device_attach() However __device_attach() may also be called asynchronously from: deferred_probe_work_func() bus_probe_device() device_initial_probe() __device_attach() So if the commit's intention was to check the "dead" flag in all asynchronous code paths, then a check is also necessary in __device_attach(). Add the missing check. Fixes: 3451a495ef24 ("driver core: Establish order of operations for device_add and device_del via bitflag") Signed-off-by: Lukas Wunner Cc: stable@vger.kernel.org # v5.1+ Cc: Alexander Duyck Link: https://lore.kernel.org/r/de88a23a6fe0ef70f7cfd13c8aea9ab51b4edab6.1594214103.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman

firmware_loader: EFI firmware loader must handle pre-allocated buffer

2020-08-19T06:24:18Z

commit 4fb60b158afd3ac9e0fe9975aa476213f5cc0a4d upstream. The EFI platform firmware fallback would clobber any pre-allocated buffers. Instead, correctly refuse to reallocate when too small (as already done in the sysfs fallback), or perform allocation normally when needed. Fixes: e4c2c0ff00ec ("firmware: Add new platform fallback mechanism and firmware_request_platform()") Cc: stable@vger.kernel.org Acked-by: Scott Branden Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20200724213640.389191-4-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman

driver core: Fix probe_count imbalance in really_probe()

2020-08-19T06:24:14Z

commit b292b50b0efcc7095d8bf15505fba6909bb35dce upstream. syzbot is reporting hung task in wait_for_device_probe() [1]. At least, we always need to decrement probe_count if we incremented probe_count in really_probe(). However, since I can't find "Resources present before probing" message in the console log, both "this message simply flowed off" and "syzbot is not hitting this path" will be possible. Therefore, while we are at it, let's also prepare for concurrent wait_for_device_probe() calls by replacing wake_up() with wake_up_all(). [1] https://syzkaller.appspot.com/bug?id=25c833f1983c9c1d512f4ff860dd0d7f5a2e2c0f Reported-by: syzbot Fixes: 7c35e699c88bd607 ("driver core: Print device when resources present in really_probe()") Cc: Geert Uytterhoeven Signed-off-by: Tetsuo Handa Cc: stable Link: https://lore.kernel.org/r/20200713021254.3444-1-penguin-kernel@I-love.SAKURA.ne.jp Signed-off-by: Greg Kroah-Hartman

regmap: debugfs: check count when read regmap file

2020-07-31T16:47:16Z

commit 74edd08a4fbf51d65fd8f4c7d8289cd0f392bd91 upstream. When executing the following command, we met kernel dump. dmesg -c > /dev/null; cd /sys; for i in `ls /sys/kernel/debug/regmap/* -d`; do echo "Checking regmap in $i"; cat $i/registers; done && grep -ri "0x02d0" *; It is because the count value is too big, and kmalloc fails. So add an upper bound check to allow max size `PAGE_SIZE << (MAX_ORDER - 1)`. Signed-off-by: Peng Fan Link: https://lore.kernel.org/r/1584064687-12964-1-git-send-email-peng.fan@nxp.com Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman

regmap: dev_get_regmap_match(): fix string comparison

2020-07-29T08:19:51Z

[ Upstream commit e84861fec32dee8a2e62bbaa52cded6b05a2a456 ] This function is used by dev_get_regmap() to retrieve a regmap for the specified device. If the device has more than one regmap, the name parameter can be used to specify one. The code here uses a pointer comparison to check for equal strings. This however will probably always fail, as the regmap->name is allocated via kstrdup_const() from the regmap's config->name. Fix this by using strcmp() instead. Signed-off-by: Marc Kleine-Budde Link: https://lore.kernel.org/r/20200703103315.267996-1-mkl@pengutronix.de Signed-off-by: Mark Brown Signed-off-by: Sasha Levin

regmap: debugfs: Don't sleep while atomic for fast_io regmaps

2020-07-22T07:34:11Z

[ Upstream commit 299632e54b2e692d2830af84be51172480dc1e26 ] If a regmap has "fast_io" set then its lock function uses a spinlock. That doesn't work so well with the functions: * regmap_cache_only_write_file() * regmap_cache_bypass_write_file() Both of the above functions have the pattern: 1. Lock the regmap. 2. Call: debugfs_write_file_bool() copy_from_user() __might_fault() __might_sleep() Let's reorder things a bit so that we do all of our sleepable functions before we grab the lock. Fixes: d3dc5430d68f ("regmap: debugfs: Allow writes to cache state settings") Signed-off-by: Douglas Anderson Link: https://lore.kernel.org/r/20200715164611.1.I35b3533e8a80efde0cec1cc70f71e1e74b2fa0da@changeid Signed-off-by: Mark Brown Signed-off-by: Sasha Levin

regmap: fix alignment issue

2020-07-16T06:13:11Z

[ Upstream commit 53d860952c8215cf9ae1ea33409c8cb71ad6ad3d ] The assembly and disassembly of data to be sent to or received from a device invoke functions regmap_format_XX() and regmap_parse_XX() that extract or insert data items from or into a buffer, using assignments. In some cases the functions are called with a buffer pointer with an odd address. On architectures with strict alignment requirements this can result in a kernel crash. The assignments have been replaced by functions that take alignment into account. Signed-off-by: Jens Thoms Toerring Link: https://lore.kernel.org/r/20200531095300.GA27570@toerring.de Signed-off-by: Mark Brown Signed-off-by: Sasha Levin

regmap: Fix memory leak from regmap_register_patch

2020-06-30T19:36:04Z

[ Upstream commit 95b2c3ec4cb1689db2389c251d39f64490ba641c ] When a register patch is registered the reg_sequence is copied but the memory allocated is never freed. Add a kfree in regmap_exit to clean it up. Fixes: 22f0d90a3482 ("regmap: Support register patch sets") Signed-off-by: Charles Keepax Link: https://lore.kernel.org/r/20200617152129.19655-1-ckeepax@opensource.cirrus.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin

drivers: base: Fix NULL pointer exception in __platform_driver_probe() if a driver developer is foolish

2020-06-24T15:48:41Z

[ Upstream commit 388bcc6ecc609fca1b4920de7dc3806c98ec535e ] If platform bus driver registration is failed then, accessing platform bus spin lock (&drv->driver.bus->p->klist_drivers.k_lock) in __platform_driver_probe() without verifying the return value __platform_driver_register() can lead to NULL pointer exception. So check the return value before attempting the spin lock. One such example is below: For a custom usecase, I have intentionally failed the platform bus registration and I expected all the platform device/driver registrations to fail gracefully. But I came across this panic issue. [ 1.331067] BUG: kernel NULL pointer dereference, address: 00000000000000c8 [ 1.331118] #PF: supervisor write access in kernel mode [ 1.331163] #PF: error_code(0x0002) - not-present page [ 1.331208] PGD 0 P4D 0 [ 1.331233] Oops: 0002 [#1] PREEMPT SMP [ 1.331268] CPU: 3 PID: 1 Comm: swapper/0 Tainted: G W 5.6.0-00049-g670d35fb0144 #165 [ 1.331341] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 [ 1.331406] RIP: 0010:_raw_spin_lock+0x15/0x30 [ 1.331588] RSP: 0000:ffffc9000001be70 EFLAGS: 00010246 [ 1.331632] RAX: 0000000000000000 RBX: 00000000000000c8 RCX: 0000000000000001 [ 1.331696] RDX: 0000000000000001 RSI: 0000000000000092 RDI: 0000000000000000 [ 1.331754] RBP: 00000000ffffffed R08: 0000000000000501 R09: 0000000000000001 [ 1.331817] R10: ffff88817abcc520 R11: 0000000000000670 R12: 00000000ffffffed [ 1.331881] R13: ffffffff82dbc268 R14: ffffffff832f070a R15: 0000000000000000 [ 1.331945] FS: 0000000000000000(0000) GS:ffff88817bd80000(0000) knlGS:0000000000000000 [ 1.332008] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1.332062] CR2: 00000000000000c8 CR3: 000000000681e001 CR4: 00000000003606e0 [ 1.332126] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 1.332189] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 1.332252] Call Trace: [ 1.332281] __platform_driver_probe+0x92/0xee [ 1.332323] ? rtc_dev_init+0x2b/0x2b [ 1.332358] cmos_init+0x37/0x67 [ 1.332396] do_one_initcall+0x7d/0x168 [ 1.332428] kernel_init_freeable+0x16c/0x1c9 [ 1.332473] ? rest_init+0xc0/0xc0 [ 1.332508] kernel_init+0x5/0x100 [ 1.332543] ret_from_fork+0x1f/0x30 [ 1.332579] CR2: 00000000000000c8 [ 1.332616] ---[ end trace 3bd87f12e9010b87 ]--- [ 1.333549] note: swapper/0[1] exited with preempt_count 1 [ 1.333592] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009 [ 1.333736] Kernel Offset: disabled Note, this can only be triggered if a driver errors out from this call, which should never happen. If it does, the driver needs to be fixed. Signed-off-by: Kuppuswamy Sathyanarayanan Link: https://lore.kernel.org/r/20200408214003.3356-1-sathyanarayanan.kuppuswamy@linux.intel.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

software node: implement software_node_unregister()

2020-06-22T07:33:04Z

commit 46d26819a5056f4831649c5887ad5c71a16d86f7 upstream. Sometimes it is better to unregister individual nodes instead of trying to do them all at once with software_node_unregister_nodes(), so create software_node_unregister() so that you can unregister them one at a time. This is especially important when creating nodes in a hierarchy, with parent -> children representations. Children always need to be removed before a parent is, as the swnode logic assumes this is going to be the case. Fix up the lib/test_printf.c fwnode_pointer() test which to use this new function as it had the problem of tearing things down in the backwards order. Fixes: f1ce39df508d ("lib/test_printf: Add tests for %pfw printk modifier") Cc: stable Cc: Andy Shevchenko Cc: Brendan Higgins Cc: Dmitry Torokhov Cc: Petr Mladek Cc: Rafael J. Wysocki Cc: Rasmus Villemoes Cc: Sakari Ailus Cc: Sergey Senozhatsky Cc: Steven Rostedt Reported-by: Naresh Kamboju Reported-by: kernel test robot Reported-by: Randy Dunlap Tested-by: Petr Mladek Tested-by: Randy Dunlap Tested-by: Guenter Roeck Reviewed-by: Heikki Krogerus Acked-by: Randy Dunlap Link: https://lore.kernel.org/r/20200524153041.2361-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman