user/sven/linux.git, branch v3.4.112

Linux 3.4.112

2016-04-27T10:55:30Z

x86/iopl/64: Properly context-switch IOPL on Xen PV

2016-04-27T10:55:30Z

commit b7a584598aea7ca73140cb87b40319944dd3393f upstream. On Xen PV, regs->flags doesn't reliably reflect IOPL and the exit-to-userspace code doesn't change IOPL. We need to context switch it manually. I'm doing this without going through paravirt because this is specific to Xen PV. After the dust settles, we can merge this with the 32-bit code, tidy up the iopl syscall implementation, and remove the set_iopl pvop entirely. Fixes XSA-171. Reviewewd-by: Jan Beulich Signed-off-by: Andy Lutomirski Cc: Andrew Cooper Cc: Andy Lutomirski Cc: Boris Ostrovsky Cc: Borislav Petkov Cc: Brian Gerst Cc: David Vrabel Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Jan Beulich Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/693c3bd7aeb4d3c27c92c622b7d0f554a458173c.1458162709.git.luto@kernel.org Signed-off-by: Ingo Molnar [ kamal: backport to 3.19-stable: no X86_FEATURE_XENPV so just call xen_pv_domain() directly ] Acked-by: Andy Lutomirski kernel.org> Signed-off-by: Kamal Mostafa canonical.com> Signed-off-by: Zefan Li

splice: sendfile() at once fails for big files

2016-04-27T10:55:30Z

commit 0ff28d9f4674d781e492bcff6f32f0fe48cf0fed upstream. Using sendfile with below small program to get MD5 sums of some files, it appear that big files (over 64kbytes with 4k pages system) get a wrong MD5 sum while small files get the correct sum. This program uses sendfile() to send a file to an AF_ALG socket for hashing. /* md5sum2.c */ #include #include #include #include #include #include #include #include #include int main(int argc, char **argv) { int sk = socket(AF_ALG, SOCK_SEQPACKET, 0); struct stat st; struct sockaddr_alg sa = { .salg_family = AF_ALG, .salg_type = "hash", .salg_name = "md5", }; int n; bind(sk, (struct sockaddr*)&sa, sizeof(sa)); for (n = 1; n < argc; n++) { int size; int offset = 0; char buf[4096]; int fd; int sko; int i; fd = open(argv[n], O_RDONLY); sko = accept(sk, NULL, 0); fstat(fd, &st); size = st.st_size; sendfile(sko, fd, &offset, size); size = read(sko, buf, sizeof(buf)); for (i = 0; i < size; i++) printf("%2.2x", buf[i]); printf(" %s\n", argv[n]); close(fd); close(sko); } exit(0); } Test below is done using official linux patch files. First result is with a software based md5sum. Second result is with the program above. root@vgoip:~# ls -l patch-3.6.* -rw-r--r-- 1 root root 64011 Aug 24 12:01 patch-3.6.2.gz -rw-r--r-- 1 root root 94131 Aug 24 12:01 patch-3.6.3.gz root@vgoip:~# md5sum patch-3.6.* b3ffb9848196846f31b2ff133d2d6443 patch-3.6.2.gz c5e8f687878457db77cb7158c38a7e43 patch-3.6.3.gz root@vgoip:~# ./md5sum2 patch-3.6.* b3ffb9848196846f31b2ff133d2d6443 patch-3.6.2.gz 5fd77b24e68bb24dcc72d6e57c64790e patch-3.6.3.gz After investivation, it appears that sendfile() sends the files by blocks of 64kbytes (16 times PAGE_SIZE). The problem is that at the end of each block, the SPLICE_F_MORE flag is missing, therefore the hashing operation is reset as if it was the end of the file. This patch adds SPLICE_F_MORE to the flags when more data is pending. With the patch applied, we get the correct sums: root@vgoip:~# md5sum patch-3.6.* b3ffb9848196846f31b2ff133d2d6443 patch-3.6.2.gz c5e8f687878457db77cb7158c38a7e43 patch-3.6.3.gz root@vgoip:~# ./md5sum2 patch-3.6.* b3ffb9848196846f31b2ff133d2d6443 patch-3.6.2.gz c5e8f687878457db77cb7158c38a7e43 patch-3.6.3.gz Signed-off-by: Christophe Leroy Signed-off-by: Jens Axboe Cc: Ben Hutchings Signed-off-by: Zefan Li

pipe: Fix buffer offset after partially failed read

2016-04-27T10:55:30Z

Quoting the RHEL advisory: > It was found that the fix for CVE-2015-1805 incorrectly kept buffer > offset and buffer length in sync on a failed atomic read, potentially > resulting in a pipe buffer state corruption. A local, unprivileged user > could use this flaw to crash the system or leak kernel memory to user > space. (CVE-2016-0774, Moderate) The same flawed fix was applied to stable branches from 2.6.32.y to 3.14.y inclusive, and I was able to reproduce the issue on 3.2.y. We need to give pipe_iov_copy_to_user() a separate offset variable and only update the buffer offset if it succeeds. References: https://rhn.redhat.com/errata/RHSA-2016-0103.html Signed-off-by: Ben Hutchings Cc: Jeffrey Vander Stoep Signed-off-by: Zefan Li

usb: Use the USB_SS_MULT() macro to decode burst multiplier for log message

2016-04-27T10:55:30Z

commit 5377adb092664d336ac212499961cac5e8728794 upstream. usb_parse_ss_endpoint_companion() now decodes the burst multiplier correctly in order to check that it's <= 3, but still uses the wrong expression if warning that it's > 3. Fixes: ff30cbc8da42 ("usb: Use the USB_SS_MULT() macro to get the ...") Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman Signed-off-by: Zefan Li

raid1: include bio_end_io_list in nr_queued to prevent freeze_array hang

2016-04-27T10:55:30Z

commit ccfc7bf1f09d6190ef86693ddc761d5fe3fa47cb upstream. If raid1d is handling a mix of read and write errors, handle_read_error's call to freeze_array can get stuck. This can happen because, though the bio_end_io_list is initially drained, writes can be added to it via handle_write_finished as the retry_list is processed. These writes contribute to nr_pending but are not included in nr_queued. If a later entry on the retry_list triggers a call to handle_read_error, freeze array hangs waiting for nr_pending == nr_queued+extra. The writes on the bio_end_io_list aren't included in nr_queued so the condition will never be satisfied. To prevent the hang, include bio_end_io_list writes in nr_queued. There's probably a better way to handle decrementing nr_queued, but this seemed like the safest way to avoid breaking surrounding code. I'm happy to supply the script I used to repro this hang. Fixes: 55ce74d4bfe1b(md/raid1: ensure device failure recorded before write request returns.) Signed-off-by: Nate Dailey Signed-off-by: Shaohua Li Signed-off-by: Zefan Li

mvsas: Fix NULL pointer dereference in mvs_slot_task_free

2016-04-27T10:55:29Z

commit 2280521719e81919283b82902ac24058f87dfc1b upstream. When pci_pool_alloc fails in mvs_task_prep then task->lldd_task stays NULL but it's later used in mvs_abort_task as slot which is passed to mvs_slot_task_free causing NULL pointer dereference. Just return from mvs_slot_task_free when passed with NULL slot. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=101891 Signed-off-by: Dāvis Mosāns Reviewed-by: Tomas Henzl Reviewed-by: Johannes Thumshirn Signed-off-by: James Bottomley Signed-off-by: Zefan Li

dm btree: fix leak of bufio-backed block in btree_split_beneath error path

2016-04-27T10:55:29Z

commit 4dcb8b57df3593dcb20481d9d6cf79d1dc1534be upstream. btree_split_beneath()'s error path had an outstanding FIXME that speaks directly to the potential for _not_ cleaning up a previously allocated bufio-backed block. Fix this by releasing the previously allocated bufio block using unlock_block(). Reported-by: Mikulas Patocka Signed-off-by: Mike Snitzer Acked-by: Joe Thornber Signed-off-by: Zefan Li

mm: make sendfile(2) killable

2016-04-27T10:55:29Z

commit 296291cdd1629c308114504b850dc343eabc2782 upstream. Currently a simple program below issues a sendfile(2) system call which takes about 62 days to complete in my test KVM instance. int fd; off_t off = 0; fd = open("file", O_RDWR | O_TRUNC | O_SYNC | O_CREAT, 0644); ftruncate(fd, 2); lseek(fd, 0, SEEK_END); sendfile(fd, fd, &off, 0xfffffff); Now you should not ask kernel to do a stupid stuff like copying 256MB in 2-byte chunks and call fsync(2) after each chunk but if you do, sysadmin should have a way to stop you. We actually do have a check for fatal_signal_pending() in generic_perform_write() which triggers in this path however because we always succeed in writing something before the check is done, we return value > 0 from generic_perform_write() and thus the information about signal gets lost. Fix the problem by doing the signal check before writing anything. That way generic_perform_write() returns -EINTR, the error gets propagated up and the sendfile loop terminates early. Signed-off-by: Jan Kara Reported-by: Dmitry Vyukov Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Zefan Li

drm/nouveau/gem: return only valid domain when there's only one

2016-04-27T10:55:29Z

commit 2a6c521bb41ce862e43db46f52e7681d33e8d771 upstream. On nv50+, we restrict the valid domains to just the one where the buffer was originally created. However after the buffer is evicted to system memory, we might move it back to a different domain that was not originally valid. When sharing the buffer and retrieving its GEM_INFO data, we still want the domain that will be valid for this buffer in a pushbuf, not the one where it currently happens to be. This resolves fdo#92504 and several others. These are due to suspend evicting all buffers, making it more likely that they temporarily end up in the wrong place. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92504 Signed-off-by: Ilia Mirkin Signed-off-by: Ben Skeggs Signed-off-by: Zefan Li