kernel/linux.git/drivers/char, branch v4.19.112

ipmi:ssif: Handle a possible NULL pointer reference

2020-03-05T15:42:12+00:00

[ Upstream commit 6b8526d3abc02c08a2f888e8c20b7ac9e5776dfe ] In error cases a NULL can be passed to memcpy. The length will always be zero, so it doesn't really matter, but go ahead and check for NULL, anyway, to be more precise and avoid static analysis errors. Reported-by: kbuild test robot Signed-off-by: Corey Minyard Signed-off-by: Sasha Levin

Revert "char/random: silence a lockdep splat with printk()"

2020-02-28T15:39:00+00:00

This reverts commit 15341b1dd409749fa5625e4b632013b6ba81609b which is commit 1b710b1b10eff9d46666064ea25f079f70bc67a8 upstream. Lech writes: After upgrading kernel on our boards from v4.19.105 to v4.19.106 we found out that syslog fails to read the messages after ones read initially after opening /proc/kmsg just after booting. I also found out, that output of 'dmesg --follow' also doesn't react on new printks appearing for whatever reason - to read new messages, reopening /proc/kmsg or /dev/kmsg was needed. I bisected this down to commit 15341b1dd409749fa5625e4b632013b6ba81609b ("char/random: silence a lockdep splat with printk()"), and reverting it on top of v4.19.106 restored correct behaviour. While people dig to find out how such an odd change causes a lockup, let's just revert this for now as it's not all that big of a deal for 4.19.y. Reported-by: Lech Perczak Signed-off-by: Greg Kroah-Hartman Cc: Sergey Senozhatsky Cc: Qian Cai Cc: Theodore Ts'o Cc: Sasha Levin Cc: Petr Mladek Cc: John Ogness Signed-off-by: Greg Kroah-Hartman

char/random: silence a lockdep splat with printk()

2020-02-24T07:34:36+00:00

[ Upstream commit 1b710b1b10eff9d46666064ea25f079f70bc67a8 ] Sergey didn't like the locking order, uart_port->lock -> tty_port->lock uart_write (uart_port->lock) __uart_start pl011_start_tx pl011_tx_chars uart_write_wakeup tty_port_tty_wakeup tty_port_default tty_port_tty_get (tty_port->lock) but those code is so old, and I have no clue how to de-couple it after checking other locks in the splat. There is an onging effort to make all printk() as deferred, so until that happens, workaround it for now as a short-term fix. LTP: starting iogen01 (export LTPROOT; rwtest -N iogen01 -i 120s -s read,write -Da -Dv -n 2 500b:$TMPDIR/doio.f1.$$ 1000b:$TMPDIR/doio.f2.$$) WARNING: possible circular locking dependency detected ------------------------------------------------------ doio/49441 is trying to acquire lock: ffff008b7cff7290 (&(&zone->lock)->rlock){..-.}, at: rmqueue+0x138/0x2050 but task is already holding lock: 60ff000822352818 (&pool->lock/1){-.-.}, at: start_flush_work+0xd8/0x3f0 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&pool->lock/1){-.-.}: lock_acquire+0x320/0x360 _raw_spin_lock+0x64/0x80 __queue_work+0x4b4/0xa10 queue_work_on+0xac/0x11c tty_schedule_flip+0x84/0xbc tty_flip_buffer_push+0x1c/0x28 pty_write+0x98/0xd0 n_tty_write+0x450/0x60c tty_write+0x338/0x474 __vfs_write+0x88/0x214 vfs_write+0x12c/0x1a4 redirected_tty_write+0x90/0xdc do_loop_readv_writev+0x140/0x180 do_iter_write+0xe0/0x10c vfs_writev+0x134/0x1cc do_writev+0xbc/0x130 __arm64_sys_writev+0x58/0x8c el0_svc_handler+0x170/0x240 el0_sync_handler+0x150/0x250 el0_sync+0x164/0x180 -> #3 (&(&port->lock)->rlock){-.-.}: lock_acquire+0x320/0x360 _raw_spin_lock_irqsave+0x7c/0x9c tty_port_tty_get+0x24/0x60 tty_port_default_wakeup+0x1c/0x3c tty_port_tty_wakeup+0x34/0x40 uart_write_wakeup+0x28/0x44 pl011_tx_chars+0x1b8/0x270 pl011_start_tx+0x24/0x70 __uart_start+0x5c/0x68 uart_write+0x164/0x1c8 do_output_char+0x33c/0x348 n_tty_write+0x4bc/0x60c tty_write+0x338/0x474 redirected_tty_write+0xc0/0xdc do_loop_readv_writev+0x140/0x180 do_iter_write+0xe0/0x10c vfs_writev+0x134/0x1cc do_writev+0xbc/0x130 __arm64_sys_writev+0x58/0x8c el0_svc_handler+0x170/0x240 el0_sync_handler+0x150/0x250 el0_sync+0x164/0x180 -> #2 (&port_lock_key){-.-.}: lock_acquire+0x320/0x360 _raw_spin_lock+0x64/0x80 pl011_console_write+0xec/0x2cc console_unlock+0x794/0x96c vprintk_emit+0x260/0x31c vprintk_default+0x54/0x7c vprintk_func+0x218/0x254 printk+0x7c/0xa4 register_console+0x734/0x7b0 uart_add_one_port+0x734/0x834 pl011_register_port+0x6c/0xac sbsa_uart_probe+0x234/0x2ec platform_drv_probe+0xd4/0x124 really_probe+0x250/0x71c driver_probe_device+0xb4/0x200 __device_attach_driver+0xd8/0x188 bus_for_each_drv+0xbc/0x110 __device_attach+0x120/0x220 device_initial_probe+0x20/0x2c bus_probe_device+0x54/0x100 device_add+0xae8/0xc2c platform_device_add+0x278/0x3b8 platform_device_register_full+0x238/0x2ac acpi_create_platform_device+0x2dc/0x3a8 acpi_bus_attach+0x390/0x3cc acpi_bus_attach+0x108/0x3cc acpi_bus_attach+0x108/0x3cc acpi_bus_attach+0x108/0x3cc acpi_bus_scan+0x7c/0xb0 acpi_scan_init+0xe4/0x304 acpi_init+0x100/0x114 do_one_initcall+0x348/0x6a0 do_initcall_level+0x190/0x1fc do_basic_setup+0x34/0x4c kernel_init_freeable+0x19c/0x260 kernel_init+0x18/0x338 ret_from_fork+0x10/0x18 -> #1 (console_owner){-...}: lock_acquire+0x320/0x360 console_lock_spinning_enable+0x6c/0x7c console_unlock+0x4f8/0x96c vprintk_emit+0x260/0x31c vprintk_default+0x54/0x7c vprintk_func+0x218/0x254 printk+0x7c/0xa4 get_random_u64+0x1c4/0x1dc shuffle_pick_tail+0x40/0xac __free_one_page+0x424/0x710 free_one_page+0x70/0x120 __free_pages_ok+0x61c/0xa94 __free_pages_core+0x1bc/0x294 memblock_free_pages+0x38/0x48 __free_pages_memory+0xcc/0xfc __free_memory_core+0x70/0x78 free_low_memory_core_early+0x148/0x18c memblock_free_all+0x18/0x54 mem_init+0xb4/0x17c mm_init+0x14/0x38 start_kernel+0x19c/0x530 -> #0 (&(&zone->lock)->rlock){..-.}: validate_chain+0xf6c/0x2e2c __lock_acquire+0x868/0xc2c lock_acquire+0x320/0x360 _raw_spin_lock+0x64/0x80 rmqueue+0x138/0x2050 get_page_from_freelist+0x474/0x688 __alloc_pages_nodemask+0x3b4/0x18dc alloc_pages_current+0xd0/0xe0 alloc_slab_page+0x2b4/0x5e0 new_slab+0xc8/0x6bc ___slab_alloc+0x3b8/0x640 kmem_cache_alloc+0x4b4/0x588 __debug_object_init+0x778/0x8b4 debug_object_init_on_stack+0x40/0x50 start_flush_work+0x16c/0x3f0 __flush_work+0xb8/0x124 flush_work+0x20/0x30 xlog_cil_force_lsn+0x88/0x204 [xfs] xfs_log_force_lsn+0x128/0x1b8 [xfs] xfs_file_fsync+0x3c4/0x488 [xfs] vfs_fsync_range+0xb0/0xd0 generic_write_sync+0x80/0xa0 [xfs] xfs_file_buffered_aio_write+0x66c/0x6e4 [xfs] xfs_file_write_iter+0x1a0/0x218 [xfs] __vfs_write+0x1cc/0x214 vfs_write+0x12c/0x1a4 ksys_write+0xb0/0x120 __arm64_sys_write+0x54/0x88 el0_svc_handler+0x170/0x240 el0_sync_handler+0x150/0x250 el0_sync+0x164/0x180 other info that might help us debug this: Chain exists of: &(&zone->lock)->rlock --> &(&port->lock)->rlock --> &pool->lock/1 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&pool->lock/1); lock(&(&port->lock)->rlock); lock(&pool->lock/1); lock(&(&zone->lock)->rlock); *** DEADLOCK *** 4 locks held by doio/49441: #0: a0ff00886fc27408 (sb_writers#8){.+.+}, at: vfs_write+0x118/0x1a4 #1: 8fff00080810dfe0 (&xfs_nondir_ilock_class){++++}, at: xfs_ilock+0x2a8/0x300 [xfs] #2: ffff9000129f2390 (rcu_read_lock){....}, at: rcu_lock_acquire+0x8/0x38 #3: 60ff000822352818 (&pool->lock/1){-.-.}, at: start_flush_work+0xd8/0x3f0 stack backtrace: CPU: 48 PID: 49441 Comm: doio Tainted: G W Hardware name: HPE Apollo 70 /C01_APACHE_MB , BIOS L50_5.13_1.11 06/18/2019 Call trace: dump_backtrace+0x0/0x248 show_stack+0x20/0x2c dump_stack+0xe8/0x150 print_circular_bug+0x368/0x380 check_noncircular+0x28c/0x294 validate_chain+0xf6c/0x2e2c __lock_acquire+0x868/0xc2c lock_acquire+0x320/0x360 _raw_spin_lock+0x64/0x80 rmqueue+0x138/0x2050 get_page_from_freelist+0x474/0x688 __alloc_pages_nodemask+0x3b4/0x18dc alloc_pages_current+0xd0/0xe0 alloc_slab_page+0x2b4/0x5e0 new_slab+0xc8/0x6bc ___slab_alloc+0x3b8/0x640 kmem_cache_alloc+0x4b4/0x588 __debug_object_init+0x778/0x8b4 debug_object_init_on_stack+0x40/0x50 start_flush_work+0x16c/0x3f0 __flush_work+0xb8/0x124 flush_work+0x20/0x30 xlog_cil_force_lsn+0x88/0x204 [xfs] xfs_log_force_lsn+0x128/0x1b8 [xfs] xfs_file_fsync+0x3c4/0x488 [xfs] vfs_fsync_range+0xb0/0xd0 generic_write_sync+0x80/0xa0 [xfs] xfs_file_buffered_aio_write+0x66c/0x6e4 [xfs] xfs_file_write_iter+0x1a0/0x218 [xfs] __vfs_write+0x1cc/0x214 vfs_write+0x12c/0x1a4 ksys_write+0xb0/0x120 __arm64_sys_write+0x54/0x88 el0_svc_handler+0x170/0x240 el0_sync_handler+0x150/0x250 el0_sync+0x164/0x180 Reviewed-by: Sergey Senozhatsky Signed-off-by: Qian Cai Link: https://lore.kernel.org/r/1573679785-21068-1-git-send-email-cai@lca.pw Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin

ttyprintk: fix a potential deadlock in interrupt context issue

2020-02-05T14:43:39+00:00

commit 9a655c77ff8fc65699a3f98e237db563b37c439b upstream. tpk_write()/tpk_close() could be interrupted when holding a mutex, then in timer handler tpk_write() may be called again trying to acquire same mutex, lead to deadlock. Google syzbot reported this issue with CONFIG_DEBUG_ATOMIC_SLEEP enabled: BUG: sleeping function called from invalid context at kernel/locking/mutex.c:938 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 0, name: swapper/1 1 lock held by swapper/1/0: ... Call Trace: dump_stack+0x197/0x210 ___might_sleep.cold+0x1fb/0x23e __might_sleep+0x95/0x190 __mutex_lock+0xc5/0x13c0 mutex_lock_nested+0x16/0x20 tpk_write+0x5d/0x340 resync_tnc+0x1b6/0x320 call_timer_fn+0x1ac/0x780 run_timer_softirq+0x6c3/0x1790 __do_softirq+0x262/0x98c irq_exit+0x19b/0x1e0 smp_apic_timer_interrupt+0x1a3/0x610 apic_timer_interrupt+0xf/0x20 See link https://syzkaller.appspot.com/bug?extid=2eeef62ee31f9460ad65 for more details. Fix it by using spinlock in process context instead of mutex and having interrupt disabled in critical section. Reported-by: syzbot+2eeef62ee31f9460ad65@syzkaller.appspotmail.com Signed-off-by: Zhenzhong Duan Cc: Arnd Bergmann Cc: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20200113034842.435-1-zhenzhong.duan@gmail.com Signed-off-by: Greg Kroah-Hartman

random: try to actively add entropy rather than passively wait for it

2020-02-01T09:37:11+00:00

commit 50ee7529ec4500c88f8664560770a7a1b65db72b upstream. For 5.3 we had to revert a nice ext4 IO pattern improvement, because it caused a bootup regression due to lack of entropy at bootup together with arguably broken user space that was asking for secure random numbers when it really didn't need to. See commit 72dbcf721566 (Revert "ext4: make __ext4_get_inode_loc plug"). This aims to solve the issue by actively generating entropy noise using the CPU cycle counter when waiting for the random number generator to initialize. This only works when you have a high-frequency time stamp counter available, but that's the case on all modern x86 CPU's, and on most other modern CPU's too. What we do is to generate jitter entropy from the CPU cycle counter under a somewhat complex load: calling the scheduler while also guaranteeing a certain amount of timing noise by also triggering a timer. I'm sure we can tweak this, and that people will want to look at other alternatives, but there's been a number of papers written on jitter entropy, and this should really be fairly conservative by crediting one bit of entropy for every timer-induced jump in the cycle counter. Not because the timer itself would be all that unpredictable, but because the interaction between the timer and the loop is going to be. Even if (and perhaps particularly if) the timer actually happens on another CPU, the cacheline interaction between the loop that reads the cycle counter and the timer itself firing is going to add perturbations to the cycle counter values that get mixed into the entropy pool. As Thomas pointed out, with a modern out-of-order CPU, even quite simple loops show a fair amount of hard-to-predict timing variability even in the absense of external interrupts. But this tries to take that further by actually having a fairly complex interaction. This is not going to solve the entropy issue for architectures that have no CPU cycle counter, but it's not clear how (and if) that is solvable, and the hardware in question is largely starting to be irrelevant. And by doing this we can at least avoid some of the even more contentious approaches (like making the entropy waiting time out in order to avoid the possibly unbounded waiting). Cc: Ahmed Darwish Cc: Thomas Gleixner Cc: Theodore Ts'o Cc: Nicholas Mc Guire Cc: Andy Lutomirski Cc: Kees Cook Cc: Willy Tarreau Cc: Alexander E. Patrakov Cc: Lennart Poettering Cc: Noah Meyerhans Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

hwrng: omap3-rom - Fix missing clock by probing with device tree

2020-01-27T13:51:20+00:00

[ Upstream commit 0c0ef9ea6f3f0d5979dc7b094b0a184c1a94716b ] Commit 0ed266d7ae5e ("clk: ti: omap3: cleanup unnecessary clock aliases") removed old omap3 clock framework aliases but caused omap3-rom-rng to stop working with clock not found error. Based on discussions on the mailing list it was requested by Tero Kristo that it would be best to fix this issue by probing omap3-rom-rng using device tree to provide a proper clk property. The other option would be to add back the missing clock alias, but that does not help moving things forward with removing old legacy platform_data. Let's also add a proper device tree binding and keep it together with the fix. Cc: devicetree@vger.kernel.org Cc: Aaro Koskinen Cc: Adam Ford Cc: Pali Rohár Cc: Rob Herring Cc: Sebastian Reichel Cc: Tero Kristo Fixes: 0ed266d7ae5e ("clk: ti: omap3: cleanup unnecessary clock aliases") Reported-by: Aaro Koskinen Signed-off-by: Tony Lindgren Acked-by: Rob Herring Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin

hwrng: bcm2835 - fix probe as platform device

2020-01-27T13:50:29+00:00

[ Upstream commit 984798de671a927ac73da31096a150df42e6aaf3 ] BCM63XX (MIPS) does not use device tree, so there cannot be any of_device_id, causing the driver to fail on probe: [ 0.904564] bcm2835-rng: probe of bcm63xx-rng failed with error -22 Fix this by checking for match data only if we are probing from device tree. Fixes: 8705f24f7b57 ("hwrng: bcm2835 - Enable BCM2835 RNG to work on BCM63xx platforms") Signed-off-by: Jonas Gorski Acked-by: Florian Fainelli Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin

ipmi: kcs_bmc: handle devm_kasprintf() failure case

2020-01-27T13:50:21+00:00

[ Upstream commit 42c7c6ef1e6fa5fc0425120f06f045190b1dda2d ] devm_kasprintf() may return NULL if internal allocation failed so this assignment is not safe. Moved the error exit path and added the !NULL which then allows the devres manager to take care of cleanup. Signed-off-by: Nicholas Mc Guire Fixes: cd2315d471f4 ("ipmi: kcs_bmc: don't change device name") Signed-off-by: Corey Minyard Reviewed-by: Haiyue Wang Signed-off-by: Sasha Levin

ipmi: Fix memory leak in __ipmi_bmc_register

2020-01-27T13:49:53+00:00

commit 4aa7afb0ee20a97fbf0c5bab3df028d5fb85fdab upstream. In the impelementation of __ipmi_bmc_register() the allocated memory for bmc should be released in case ida_simple_get() fails. Fixes: 68e7e50f195f ("ipmi: Don't use BMC product/dev ids in the BMC name") Signed-off-by: Navid Emamdoost Message-Id: <20191021200649.1511-1-navid.emamdoost@gmail.com> Signed-off-by: Corey Minyard Signed-off-by: Greg Kroah-Hartman

ipmi: Don't allow device module unload when in use

2019-12-31T15:35:23+00:00

[ Upstream commit cbb79863fc3175ed5ac506465948b02a893a8235 ] If something has the IPMI driver open, don't allow the device module to be unloaded. Before it would unload and the user would get errors on use. This change is made on user request, and it makes it consistent with the I2C driver, which has the same behavior. It does change things a little bit with respect to kernel users. If the ACPI or IPMI watchdog (or any other kernel user) has created a user, then the device module cannot be unloaded. Before it could be unloaded, This does not affect hot-plug. If the device goes away (it's on something removable that is removed or is hot-removed via sysfs) then it still behaves as it did before. Reported-by: tony camuso Signed-off-by: Corey Minyard Tested-by: tony camuso Signed-off-by: Sasha Levin