user/sven/linux.git/drivers/char, branch v3.4.40

virtio: rng: disallow multiple device registrations, fixes crashes

2013-03-20T20:04:57Z

commit e84e7a56a3aa2963db506299e29a5f3f09377f9b upstream. The code currently only supports one virtio-rng device at a time. Invoking guests with multiple devices causes the guest to blow up. Check if we've already registered and initialised the driver. Also cleanup in case of registration errors or hot-unplug so that a new device can be used. Reported-by: Peter Krempa Reported-by: Signed-off-by: Amit Shah Signed-off-by: Rusty Russell Signed-off-by: Greg Kroah-Hartman

hw_random: make buffer usable in scatterlist.

2013-03-14T18:29:42Z

commit f7f154f1246ccc5a0a7e9ce50932627d60a0c878 upstream. virtio_rng feeds the randomness buffer handed by the core directly into the scatterlist, since commit bb347d98079a547e80bd4722dee1de61e4dca0e8. However, if CONFIG_HW_RANDOM=m, the static buffer isn't a linear address (at least on most archs). We could fix this in virtio_rng, but it's actually far easier to just do it in the core as virtio_rng would have to allocate a buffer every time (it doesn't know how much the core will want to read). Reported-by: Aurelien Jarno Tested-by: Aurelien Jarno Signed-off-by: Rusty Russell Signed-off-by: Greg Kroah-Hartman

virtio_console: Don't access uninitialized data.

2013-02-14T18:48:51Z

commit aded024a12b32fc1ed9a80639681daae2d07ec25 upstream. Don't access uninitialized work-queue when removing device. The work queue is initialized only if the device multi-queue. So don't call cancel_work unless this is a multi-queue device. This fixes the following panic: Kernel panic - not syncing: BUG! Call Trace: 62031b28: [<6026085d>] panic+0x16b/0x2d3 62031b30: [<6004ef5e>] flush_work+0x0/0x1d7 62031b60: [<602606f2>] panic+0x0/0x2d3 62031b68: [<600333b0>] memcpy+0x0/0x140 62031b80: [<6002d58a>] unblock_signals+0x0/0x84 62031ba0: [<602609c5>] printk+0x0/0xa0 62031bd8: [<60264e51>] __mutex_unlock_slowpath+0x13d/0x148 62031c10: [<6004ef5e>] flush_work+0x0/0x1d7 62031c18: [<60050234>] try_to_grab_pending+0x0/0x17e 62031c38: [<6004e984>] get_work_gcwq+0x71/0x8f 62031c48: [<60050539>] __cancel_work_timer+0x5b/0x115 62031c78: [<628acc85>] unplug_port+0x0/0x191 [virtio_console] 62031c98: [<6005061c>] cancel_work_sync+0x12/0x14 62031ca8: [<628ace96>] virtcons_remove+0x80/0x15c [virtio_console] 62031ce8: [<628191de>] virtio_dev_remove+0x1e/0x7e [virtio] 62031d08: [<601cf242>] __device_release_driver+0x75/0xe4 62031d28: [<601cf2dd>] device_release_driver+0x2c/0x40 62031d48: [<601ce0dd>] driver_unbind+0x7d/0xc6 62031d88: [<601cd5d9>] drv_attr_store+0x27/0x29 62031d98: [<60115f61>] sysfs_write_file+0x100/0x14d 62031df8: [<600b737d>] vfs_write+0xcb/0x184 62031e08: [<600b58b8>] filp_close+0x88/0x94 62031e38: [<600b7686>] sys_write+0x59/0x88 62031e88: [<6001ced1>] handle_syscall+0x5d/0x80 62031ea8: [<60030a74>] userspace+0x405/0x531 62031f08: [<600d32cc>] sys_dup+0x0/0x5e 62031f28: [<601b11d6>] strcpy+0x0/0x18 62031f38: [<600be46c>] do_execve+0x10/0x12 62031f48: [<600184c7>] run_init_process+0x43/0x45 62031fd8: [<60019a91>] new_thread_handler+0xba/0xbc Signed-off-by: Sjur Brændeland Signed-off-by: Rusty Russell Signed-off-by: Greg Kroah-Hartman

tpm: Propagate error from tpm_transmit to fix a timeout hang

2012-10-21T16:28:01Z

commit abce9ac292e13da367bbd22c1f7669f988d931ac upstream. tpm_write calls tpm_transmit without checking the return value and assigns the return value unconditionally to chip->pending_data, even if it's an error value. This causes three bugs. So if we write to /dev/tpm0 with a tpm_param_size bigger than TPM_BUFSIZE=0x1000 (e.g. 0x100a) and a bufsize also bigger than TPM_BUFSIZE (e.g. 0x100a) tpm_transmit returns -E2BIG which is assigned to chip->pending_data as -7, but tpm_write returns that TPM_BUFSIZE bytes have been successfully been written to the TPM, altough this is not true (bug #1). As we did write more than than TPM_BUFSIZE bytes but tpm_write reports that only TPM_BUFSIZE bytes have been written the vfs tries to write the remaining bytes (in this case 10 bytes) to the tpm device driver via tpm_write which then blocks at /* cannot perform a write until the read has cleared either via tpm_read or a user_read_timer timeout */ while (atomic_read(&chip->data_pending) != 0) msleep(TPM_TIMEOUT); for 60 seconds, since data_pending is -7 and nobody is able to read it (since tpm_read luckily checks if data_pending is greater than 0) (#bug 2). After that the remaining bytes are written to the TPM which are interpreted by the tpm as a normal command. (bug #3) So if the last bytes of the command stream happen to be a e.g. tpm_force_clear this gets accidentally sent to the TPM. This patch fixes all three bugs, by propagating the error code of tpm_write and returning -E2BIG if the input buffer is too big, since the response from the tpm for a truncated value is bogus anyway. Moreover it returns -EBUSY to userspace if there is a response ready to be read. Signed-off-by: Peter Huewe Signed-off-by: Kent Yoder Signed-off-by: Greg Kroah-Hartman

TTY: ttyprintk, don't touch behind tty->write_buf

2012-10-07T15:32:24Z

commit ee8b593affdf893012e57f4c54a21984d1b0d92e upstream. If a user provides a buffer larger than a tty->write_buf chunk and passes '\r' at the end of the buffer, we touch an out-of-bound memory. Add a check there to prevent this. Signed-off-by: Jiri Slaby Cc: Samo Pogacnik Signed-off-by: Greg Kroah-Hartman

random: mix in architectural randomness in extract_buf()

2012-08-15T15:10:30Z

commit d2e7c96af1e54b507ae2a6a7dd2baf588417a7e5 upstream. Mix in any architectural randomness in extract_buf() instead of xfer_secondary_buf(). This allows us to mix in more architectural randomness, and it also makes xfer_secondary_buf() faster, moving a tiny bit of additional CPU overhead to process which is extracting the randomness. [ Commit description modified by tytso to remove an extended advertisement for the RDRAND instruction. ] Signed-off-by: H. Peter Anvin Acked-by: Ingo Molnar Cc: DJ Johnston Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

random: Add comment to random_initialize()

2012-08-15T15:10:29Z

commit cbc96b7594b5691d61eba2db8b2ea723645be9ca upstream. Many platforms have per-machine instance data (serial numbers, asset tags, etc.) squirreled away in areas that are accessed during early system bringup. Mixing this data into the random pools has a very high value in providing better random data, so we should allow (and even encourage) architecture code to call add_device_randomness() from the setup_arch() paths. However, this limits our options for internal structure of the random driver since random_initialize() is not called until long after setup_arch(). Add a big fat comment to rand_initialize() spelling out this requirement. Suggested-by: Theodore Ts'o Signed-off-by: Tony Luck Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

random: remove rand_initialize_irq()

2012-08-15T15:10:29Z

commit c5857ccf293968348e5eb4ebedc68074de3dcda6 upstream. With the new interrupt sampling system, we are no longer using the timer_rand_state structure in the irq descriptor, so we can stop initializing it now. [ Merged in fixes from Sedat to find some last missing references to rand_initialize_irq() ] Signed-off-by: "Theodore Ts'o" Signed-off-by: Sedat Dilek Signed-off-by: Greg Kroah-Hartman

random: add tracepoints for easier debugging and verification

2012-08-15T15:10:28Z

commit 00ce1db1a634746040ace24c09a4e3a7949a3145 upstream. Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman

random: add new get_random_bytes_arch() function

2012-08-15T15:10:28Z

commit c2557a303ab6712bb6e09447df828c557c710ac9 upstream. Create a new function, get_random_bytes_arch() which will use the architecture-specific hardware random number generator if it is present. Change get_random_bytes() to not use the HW RNG, even if it is avaiable. The reason for this is that the hw random number generator is fast (if it is present), but it requires that we trust the hardware manufacturer to have not put in a back door. (For example, an increasing counter encrypted by an AES key known to the NSA.) It's unlikely that Intel (for example) was paid off by the US Government to do this, but it's impossible for them to prove otherwise --- especially since Bull Mountain is documented to use AES as a whitener. Hence, the output of an evil, trojan-horse version of RDRAND is statistically indistinguishable from an RDRAND implemented to the specifications claimed by Intel. Short of using a tunnelling electronic microscope to reverse engineer an Ivy Bridge chip and disassembling and analyzing the CPU microcode, there's no way for us to tell for sure. Since users of get_random_bytes() in the Linux kernel need to be able to support hardware systems where the HW RNG is not present, most time-sensitive users of this interface have already created their own cryptographic RNG interface which uses get_random_bytes() as a seed. So it's much better to use the HW RNG to improve the existing random number generator, by mixing in any entropy returned by the HW RNG into /dev/random's entropy pool, but to always _use_ /dev/random's entropy pool. This way we get almost of the benefits of the HW RNG without any potential liabilities. The only benefits we forgo is the speed/performance enhancements --- and generic kernel code can't depend on depend on get_random_bytes() having the speed of a HW RNG anyway. For those places that really want access to the arch-specific HW RNG, if it is available, we provide get_random_bytes_arch(). Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman