user/sven/linux.git/drivers/char, branch v4.9.196

ipmi_si: Only schedule continuously in the thread in maintenance mode

2019-10-07T16:53:10Z

[ Upstream commit 340ff31ab00bca5c15915e70ad9ada3030c98cf8 ] ipmi_thread() uses back-to-back schedule() to poll for command completion which, on some machines, can push up CPU consumption and heavily tax the scheduler locks leading to noticeable overall performance degradation. This was originally added so firmware updates through IPMI would complete in a timely manner. But we can't kill the scheduler locks for that one use case. Instead, only run schedule() continuously in maintenance mode, where firmware updates should run. Signed-off-by: Corey Minyard Signed-off-by: Sasha Levin

hwrng: core - don't wait on add_early_randomness()

2019-10-05T10:30:36Z

commit 78887832e76541f77169a24ac238fccb51059b63 upstream. add_early_randomness() is called by hwrng_register() when the hardware is added. If this hardware and its module are present at boot, and if there is no data available the boot hangs until data are available and can't be interrupted. For instance, in the case of virtio-rng, in some cases the host can be not able to provide enough entropy for all the guests. We can have two easy ways to reproduce the problem but they rely on misconfiguration of the hypervisor or the egd daemon: - if virtio-rng device is configured to connect to the egd daemon of the host but when the virtio-rng driver asks for data the daemon is not connected, - if virtio-rng device is configured to connect to the egd daemon of the host but the egd daemon doesn't provide data. The guest kernel will hang at boot until the virtio-rng driver provides enough data. To avoid that, call rng_get_data() in non-blocking mode (wait=0) from add_early_randomness(). Signed-off-by: Laurent Vivier Fixes: d9e797261933 ("hwrng: add randomness to system from rng...") Cc: Reviewed-by: Theodore Ts'o Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

/dev/mem: Bail out upon SIGKILL.

2019-10-05T10:30:35Z

commit 8619e5bdeee8b2c685d686281f2d2a6017c4bc15 upstream. syzbot found that a thread can stall for minutes inside read_mem() or write_mem() after that thread was killed by SIGKILL [1]. Reading from iomem areas of /dev/mem can be slow, depending on the hardware. While reading 2GB at one read() is legal, delaying termination of killed thread for minutes is bad. Thus, allow reading/writing /dev/mem and /dev/kmem to be preemptible and killable. [ 1335.912419][T20577] read_mem: sz=4096 count=2134565632 [ 1335.943194][T20577] read_mem: sz=4096 count=2134561536 [ 1335.978280][T20577] read_mem: sz=4096 count=2134557440 [ 1336.011147][T20577] read_mem: sz=4096 count=2134553344 [ 1336.041897][T20577] read_mem: sz=4096 count=2134549248 Theoretically, reading/writing /dev/mem and /dev/kmem can become "interruptible". But this patch chose "killable". Future patch will make them "interruptible" so that we can revert to "killable" if some program regressed. [1] https://syzkaller.appspot.com/bug?id=a0e3436829698d5824231251fad9d8e998f94f5e Signed-off-by: Tetsuo Handa Cc: stable Reported-by: syzbot Link: https://lore.kernel.org/r/1566825205-10703-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman

hpet: Fix division by zero in hpet_time_div()

2019-08-04T07:33:43Z

commit 0c7d37f4d9b8446956e97b7c5e61173cdb7c8522 upstream. The base value in do_div() called by hpet_time_div() is truncated from unsigned long to uint32_t, resulting in a divide-by-zero exception. UBSAN: Undefined behaviour in ../drivers/char/hpet.c:572:2 division by zero CPU: 1 PID: 23682 Comm: syz-executor.3 Not tainted 4.4.184.x86_64+ #4 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 0000000000000000 b573382df1853d00 ffff8800a3287b98 ffffffff81ad7561 ffff8800a3287c00 ffffffff838b35b0 ffffffff838b3860 ffff8800a3287c20 0000000000000000 ffff8800a3287bb0 ffffffff81b8f25e ffffffff838b35a0 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x120 lib/dump_stack.c:51 [] ubsan_epilogue+0x12/0x8d lib/ubsan.c:166 [] __ubsan_handle_divrem_overflow+0x282/0x2c8 lib/ubsan.c:262 [] hpet_time_div drivers/char/hpet.c:572 [inline] [] hpet_ioctl_common drivers/char/hpet.c:663 [inline] [] hpet_ioctl_common.cold+0xa8/0xad drivers/char/hpet.c:577 [] hpet_ioctl+0xc6/0x180 drivers/char/hpet.c:676 [] vfs_ioctl fs/ioctl.c:43 [inline] [] file_ioctl fs/ioctl.c:470 [inline] [] do_vfs_ioctl+0x6e0/0xf70 fs/ioctl.c:605 [] SYSC_ioctl fs/ioctl.c:622 [inline] [] SyS_ioctl+0x94/0xc0 fs/ioctl.c:613 [] tracesys_phase2+0x90/0x95 The main C reproducer autogenerated by syzkaller, syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); memcpy((void*)0x20000100, "/dev/hpet\000", 10); syscall(__NR_openat, 0xffffffffffffff9c, 0x20000100, 0, 0); syscall(__NR_ioctl, r[0], 0x40086806, 0x40000000000000); Fix it by using div64_ul(). Signed-off-by: Kefeng Wang Signed-off-by: Zhang HongJun Cc: stable Reviewed-by: Arnd Bergmann Link: https://lore.kernel.org/r/20190711132757.130092-1-wangkefeng.wang@huawei.com Signed-off-by: Greg Kroah-Hartman

virtio_console: initialize vtermno value for ports

2019-05-31T13:48:29Z

[ Upstream commit 4b0a2c5ff7215206ea6135a405f17c5f6fca7d00 ] For regular serial ports we do not initialize value of vtermno variable. A garbage value is assigned for non console ports. The value can be observed as a random integer with [1]. [1] vim /sys/kernel/debug/virtio-ports/vport*p* This patch initialize the value of vtermno for console serial ports to '1' and regular serial ports are initiaized to '0'. Reported-by: siliu@redhat.com Signed-off-by: Pankaj Gupta Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

ipmi:ssif: compare block number correctly for multi-part return messages

2019-05-21T16:49:00Z

commit 55be8658c7e2feb11a5b5b33ee031791dbd23a69 upstream. According to ipmi spec, block number is a number that is incremented, starting with 0, for each new block of message data returned using the middle transaction. Here, the 'blocknum' is data[0] which always starts from zero(0) and 'ssif_info->multi_pos' starts from 1. So, we need to add +1 to blocknum while comparing with multi_pos. Fixes: 7d6380cd40f79 ("ipmi:ssif: Fix handling of multi-part return messages"). Reported-by: Kiran Kolukuluru Signed-off-by: Kamlakant Patel Message-Id: <1556106615-18722-1-git-send-email-kamlakantp@marvell.com> [Also added a debug log if the block numbers don't match.] Signed-off-by: Corey Minyard Cc: stable@vger.kernel.org # 4.4 Signed-off-by: Greg Kroah-Hartman

tpm/tpm_i2c_atmel: Return -E2BIG when the transfer is incomplete

2019-04-27T07:34:41Z

commit 442601e87a4769a8daba4976ec3afa5222ca211d upstream Return -E2BIG when the transfer is incomplete. The upper layer does not retry, so not doing that is incorrect behaviour. Cc: stable@vger.kernel.org Fixes: a2871c62e186 ("tpm: Add support for Atmel I2C TPMs") Signed-off-by: Jarkko Sakkinen Reviewed-by: Stefan Berger Reviewed-by: Jerry Snitselaar Signed-off-by: Sasha Levin

tpm/tpm_crb: Avoid unaligned reads in crb_recv()

2019-04-20T07:07:54Z

commit 3d7a850fdc1a2e4d2adbc95cc0fc962974725e88 upstream The current approach to read first 6 bytes from the response and then tail of the response, can cause the 2nd memcpy_fromio() to do an unaligned read (e.g. read 32-bit word from address aligned to a 16-bits), depending on how memcpy_fromio() is implemented. If this happens, the read will fail and the memory controller will fill the read with 1's. This was triggered by 170d13ca3a2f, which should be probably refined to check and react to the address alignment. Before that commit, on x86 memcpy_fromio() turned out to be memcpy(). By a luck GCC has done the right thing (from tpm_crb's perspective) for us so far, but we should not rely on that. Thus, it makes sense to fix this also in tpm_crb, not least because the fix can be then backported to stable kernels and make them more robust when compiled in differing environments. Cc: stable@vger.kernel.org Cc: James Morris Cc: Tomas Winkler Cc: Jerry Snitselaar Fixes: 30fc8d138e91 ("tpm: TPM 2.0 CRB Interface") Signed-off-by: Jarkko Sakkinen Reviewed-by: Jerry Snitselaar Acked-by: Tomas Winkler Signed-off-by: Sasha Levin (Microsoft)

tty: mark Siemens R3964 line discipline as BROKEN

2019-04-17T06:36:44Z

commit c7084edc3f6d67750f50d4183134c4fb5712a5c8 upstream. The n_r3964 line discipline driver was written in a different time, when SMP machines were rare, and users were trusted to do the right thing. Since then, the world has moved on but not this code, it has stayed rooted in the past with its lovely hand-crafted list structures and loads of "interesting" race conditions all over the place. After attempting to clean up most of the issues, I just gave up and am now marking the driver as BROKEN so that hopefully someone who has this hardware will show up out of the woodwork (I know you are out there!) and will help with debugging a raft of changes that I had laying around for the code, but was too afraid to commit as odds are they would break things. Many thanks to Jann and Linus for pointing out the initial problems in this codebase, as well as many reviews of my attempts to fix the issues. It was a case of whack-a-mole, and as you can see, the mole won. Reported-by: Jann Horn Signed-off-by: Greg Kroah-Hartman Signed-off-by: Linus Torvalds

hpet: Fix missing '=' character in the __setup() code of hpet_mmap_enable

2019-04-05T20:29:14Z

[ Upstream commit 24d48a61f2666630da130cc2ec2e526eacf229e3 ] Commit '3d035f580699 ("drivers/char/hpet.c: allow user controlled mmap for user processes")' introduced a new kernel command line parameter hpet_mmap, that is required to expose the memory map of the HPET registers to user-space. Unfortunately the kernel command line parameter 'hpet_mmap' is broken and never takes effect due to missing '=' character in the __setup() code of hpet_mmap_enable. Before this patch: dmesg output with the kernel command line parameter hpet_mmap=1 [ 0.204152] HPET mmap disabled dmesg output with the kernel command line parameter hpet_mmap=0 [ 0.204192] HPET mmap disabled After this patch: dmesg output with the kernel command line parameter hpet_mmap=1 [ 0.203945] HPET mmap enabled dmesg output with the kernel command line parameter hpet_mmap=0 [ 0.204652] HPET mmap disabled Fixes: 3d035f580699 ("drivers/char/hpet.c: allow user controlled mmap for user processes") Signed-off-by: Buland Singh Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin