- 26 Feb, 2017 5 commits
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Ben Hutchings authored
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Eric Dumazet authored
commit ccf7abb9 upstream. Splicing from TCP socket is vulnerable when a packet with URG flag is received and stored into receive queue. __tcp_splice_read() returns 0, and sk_wait_data() immediately returns since there is the problematic skb in queue. This is a nice way to burn cpu (aka infinite loop) and trigger soft lockups. Again, this gem was found by syzkaller tool. Fixes: 9c55e01c ("[TCP]: Splice receive support.") Signed-off-by:
Eric Dumazet <edumazet@google.com> Reported-by:
Dmitry Vyukov <dvyukov@google.com> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by:
David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: adjust context] Signed-off-by:
Ben Hutchings <ben@decadent.org.uk>
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Andrey Konovalov authored
commit 5edabca9 upstream. In the current DCCP implementation an skb for a DCCP_PKT_REQUEST packet is forcibly freed via __kfree_skb in dccp_rcv_state_process if dccp_v6_conn_request successfully returns. However, if IPV6_RECVPKTINFO is set on a socket, the address of the skb is saved to ireq->pktopts and the ref count for skb is incremented in dccp_v6_conn_request, so skb is still in use. Nevertheless, it gets freed in dccp_rcv_state_process. Fix by calling consume_skb instead of doing goto discard and therefore calling __kfree_skb. Similar fixes for TCP: fb7e2399 [TCP]: skb is unexpectedly freed. 0aea76d3 tcp: SYN packets are now simply consumed Signed-off-by:
Andrey Konovalov <andreyknvl@google.com> Acked-by:
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Johan Hovold authored
commit 146cc8a1 upstream. The current implementation failed to detect short transfers when attempting to read the line state, and also, to make things worse, logged the content of the uninitialised heap transfer buffer. Fixes: abf492e7 ("USB: kl5kusb105: fix DMA buffers on stack") Fixes: 1da177e4 ("Linux-2.6.12-rc2") Reviewed-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by:
Johan Hovold <johan@kernel.org> Signed-off-by:
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Jim Mattson authored
commit ef85b673 upstream. When L2 exits to L0 due to "exception or NMI", software exceptions (#BP and #OF) for which L1 has requested an intercept should be handled by L1 rather than L0. Previously, only hardware exceptions were forwarded to L1. Signed-off-by:
Jim Mattson <jmattson@google.com> Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com> [bwh: Backported to 3.2: adjust context] Signed-off-by:
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- 23 Feb, 2017 35 commits
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Ben Hutchings authored
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Takashi Iwai authored
commit 3aa02cb6 upstream. Currently kill_fasync() is called outside the stream lock in snd_pcm_period_elapsed(). This is potentially racy, since the stream may get released even during the irq handler is running. Although snd_pcm_release_substream() calls snd_pcm_drop(), this doesn't guarantee that the irq handler finishes, thus the kill_fasync() call outside the stream spin lock may be invoked after the substream is detached, as recently reported by KASAN. As a quick workaround, move kill_fasync() call inside the stream lock. The fasync is rarely used interface, so this shouldn't have a big impact from the performance POV. Ideally, we should implement some sync mechanism for the proper finish of stream and irq handler. But this oneliner should suffice for most cases, so far. Reported-by:
Baozeng Ding <sploving1@gmail.com> Signed-off-by:
Takashi Iwai <tiwai@suse.de> [bwh: Backported to 3.2: adjust context] Signed-off-by:
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Eric Dumazet authored
commit b98b0bc8 upstream. CAP_NET_ADMIN users should not be allowed to set negative sk_sndbuf or sk_rcvbuf values, as it can lead to various memory corruptions, crashes, OOM... Note that before commit 82981930 ("net: cleanups in sock_setsockopt()"), the bug was even more serious, since SO_SNDBUF and SO_RCVBUF were vulnerable. This needs to be backported to all known linux kernels. Again, many thanks to syzkaller team for discovering this gem. Signed-off-by:
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Al Viro authored
commit a0ac402c upstream. Both damn things interpret userland pointers embedded into the payload; worse, they are actually traversing those. Leaving aside the bad API design, this is very much _not_ safe to call with KERNEL_DS. Bail out early if that happens. Cc: stable@vger.kernel.org Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
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Marcelo Ricardo Leitner authored
commit bf911e98 upstream. Andrey Konovalov reported that KASAN detected that SCTP was using a slab beyond the boundaries. It was caused because when handling out of the blue packets in function sctp_sf_ootb() it was checking the chunk len only after already processing the first chunk, validating only for the 2nd and subsequent ones. The fix is to just move the check upwards so it's also validated for the 1st chunk. Reported-by:
Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Reviewed-by:
Xin Long <lucien.xin@gmail.com> Acked-by:
Neil Horman <nhorman@tuxdriver.com> Signed-off-by:
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Linus Torvalds authored
Not upstream as it is not needed there. So a patch something like this might be a safe way to fix the potential infoleak in older kernels. THIS IS UNTESTED. It's a very obvious patch, though, so if it compiles it probably works. It just initializes the output variable with 0 in the inline asm description, instead of doing it in the exception handler. It will generate slightly worse code (a few unnecessary ALU operations), but it doesn't have any interactions with the exception handler implementation. Signed-off-by:
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Eric Dumazet authored
commit ac6e7800 upstream. With syzkaller help, Marco Grassi found a bug in TCP stack, crashing in tcp_collapse() Root cause is that sk_filter() can truncate the incoming skb, but TCP stack was not really expecting this to happen. It probably was expecting a simple DROP or ACCEPT behavior. We first need to make sure no part of TCP header could be removed. Then we need to adjust TCP_SKB_CB(skb)->end_seq Many thanks to syzkaller team and Marco for giving us a reproducer. Signed-off-by:
Marco Grassi <marco.gra@gmail.com> Reported-by:
Vladis Dronov <vdronov@redhat.com> Signed-off-by:
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Willem de Bruijn authored
commit 4f0c40d9 upstream. Dccp verifies packet integrity, including length, at initial rcv in dccp_invalid_packet, later pulls headers in dccp_enqueue_skb. A call to sk_filter in-between can cause __skb_pull to wrap skb->len. skb_copy_datagram_msg interprets this as a negative value, so (correctly) fails with EFAULT. The negative length is reported in ioctl SIOCINQ or possibly in a DCCP_WARN in dccp_close. Introduce an sk_receive_skb variant that caps how small a filter program can trim packets, and call this in dccp with the header length. Excessively trimmed packets are now processed normally and queued for reception as 0B payloads. Fixes: 7c657876 ("[DCCP]: Initial implementation") Signed-off-by:
Willem de Bruijn <willemb@google.com> Acked-by:
Daniel Borkmann <daniel@iogearbox.net> Signed-off-by:
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Willem de Bruijn authored
commit f4979fce upstream. Sockets can have a filter program attached that drops or trims incoming packets based on the filter program return value. Rose requires data packets to have at least ROSE_MIN_LEN bytes. It verifies this on arrival in rose_route_frame and unconditionally pulls the bytes in rose_recvmsg. The filter can trim packets to below this value in-between, causing pull to fail, leaving the partial header at the time of skb_copy_datagram_msg. Place a lower bound on the size to which sk_filter may trim packets by introducing sk_filter_trim_cap and call this for rose packets. Signed-off-by:
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Ben Hutchings authored
Extraxcted from commit e6afc8ac "udp: remove headers from UDP packets before queueing". Signed-off-by:
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Kees Cook authored
commit 2dc705a9 upstream. Copying color maps to userspace doesn't check the value of to->start, which will cause kernel heap buffer OOB read due to signedness wraps. CVE-2016-8405 Link: http://lkml.kernel.org/r/20170105224249.GA50925@beast Fixes: 1da177e4 ("Linux-2.6.12-rc2") Signed-off-by:
Kees Cook <keescook@chromium.org> Reported-by: Peter Pi (@heisecode) of Trend Micro Cc: Min Chong <mchong@google.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> [bwh: Backported to 3.2: adjust filename] Signed-off-by:
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Benjamin Tissoires authored
commit 50220dea upstream. Plugging a Logitech DJ receiver with KASAN activated raises a bunch of out-of-bound readings. The fields are allocated up to MAX_USAGE, meaning that potentially, we do not have enough fields to fit the incoming values. Add checks and silence KASAN. Signed-off-by:
Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by:
Jiri Kosina <jkosina@suse.cz> Signed-off-by:
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Omar Sandoval authored
commit 8ba86821 upstream. get_task_ioprio() accesses the task->io_context without holding the task lock and thus can race with exit_io_context(), leading to a use-after-free. The reproducer below hits this within a few seconds on my 4-core QEMU VM: #define _GNU_SOURCE #include <assert.h> #include <unistd.h> #include <sys/syscall.h> #include <sys/wait.h> int main(int argc, char **argv) { pid_t pid, child; long nproc, i; /* ioprio_set(IOPRIO_WHO_PROCESS, 0, IOPRIO_PRIO_VALUE(IOPRIO_CLASS_IDLE, 0)); */ syscall(SYS_ioprio_set, 1, 0, 0x6000); nproc = sysconf(_SC_NPROCESSORS_ONLN); for (i = 0; i < nproc; i++) { pid = fork(); assert(pid != -1); if (pid == 0) { for (;;) { pid = fork(); assert(pid != -1); if (pid == 0) { _exit(0); } else { child = wait(NULL); assert(child == pid); } } } pid = fork(); assert(pid != -1); if (pid == 0) { for (;;) { /* ioprio_get(IOPRIO_WHO_PGRP, 0); */ syscall(SYS_ioprio_get, 2, 0); } } } for (;;) { /* ioprio_get(IOPRIO_WHO_PGRP, 0); */ syscall(SYS_ioprio_get, 2, 0); } return 0; } This gets us KASAN dumps like this: [ 35.526914] ================================================================== [ 35.530009] BUG: KASAN: out-of-bounds in get_task_ioprio+0x7b/0x90 at addr ffff880066f34e6c [ 35.530009] Read of size 2 by task ioprio-gpf/363 [ 35.530009] ============================================================================= [ 35.530009] BUG blkdev_ioc (Not tainted): kasan: bad access detected [ 35.530009] ----------------------------------------------------------------------------- [ 35.530009] Disabling lock debugging due to kernel taint [ 35.530009] INFO: Allocated in create_task_io_context+0x2b/0x370 age=0 cpu=0 pid=360 [ 35.530009] ___slab_alloc+0x55d/0x5a0 [ 35.530009] __slab_alloc.isra.20+0x2b/0x40 [ 35.530009] kmem_cache_alloc_node+0x84/0x200 [ 35.530009] create_task_io_context+0x2b/0x370 [ 35.530009] get_task_io_context+0x92/0xb0 [ 35.530009] copy_process.part.8+0x5029/0x5660 [ 35.530009] _do_fork+0x155/0x7e0 [ 35.530009] SyS_clone+0x19/0x20 [ 35.530009] do_syscall_64+0x195/0x3a0 [ 35.530009] return_from_SYSCALL_64+0x0/0x6a [ 35.530009] INFO: Freed in put_io_context+0xe7/0x120 age=0 cpu=0 pid=1060 [ 35.530009] __slab_free+0x27b/0x3d0 [ 35.530009] kmem_cache_free+0x1fb/0x220 [ 35.530009] put_io_context+0xe7/0x120 [ 35.530009] put_io_context_active+0x238/0x380 [ 35.530009] exit_io_context+0x66/0x80 [ 35.530009] do_exit+0x158e/0x2b90 [ 35.530009] do_group_exit+0xe5/0x2b0 [ 35.530009] SyS_exit_group+0x1d/0x20 [ 35.530009] entry_SYSCALL_64_fastpath+0x1a/0xa4 [ 35.530009] INFO: Slab 0xffffea00019bcd00 objects=20 used=4 fp=0xffff880066f34ff0 flags=0x1fffe0000004080 [ 35.530009] INFO: Object 0xffff880066f34e58 @offset=3672 fp=0x0000000000000001 [ 35.530009] ================================================================== Fix it by grabbing the task lock while we poke at the io_context. Reported-by:
Omar Sandoval <osandov@fb.com> Signed-off-by:
Jens Axboe <axboe@fb.com> [bwh: Backported to 3.2: adjust filename] Signed-off-by:
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Peter Zijlstra authored
commit 321027c1 upstream. Di Shen reported a race between two concurrent sys_perf_event_open() calls where both try and move the same pre-existing software group into a hardware context. The problem is exactly that described in commit: f63a8daa ("perf: Fix event->ctx locking") ... where, while we wait for a ctx->mutex acquisition, the event->ctx relation can have changed under us. That very same commit failed to recognise sys_perf_event_context() as an external access vector to the events and thereby didn't apply the established locking rules correctly. So while one sys_perf_event_open() call is stuck waiting on mutex_lock_double(), the other (which owns said locks) moves the group about. So by the time the former sys_perf_event_open() acquires the locks, the context we've acquired is stale (and possibly dead). Apply the established locking rules as per perf_event_ctx_lock_nested() to the mutex_lock_double() for the 'move_group' case. This obviously means we need to validate state after we acquire the locks. Reported-by: Di Shen (Keen Lab) Tested-by:
John Dias <joaodias@google.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Min Chong <mchong@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Fixes: f63a8daa ("perf: Fix event->ctx locking") Link: http://lkml.kernel.org/r/20170106131444.GZ3174@twins.programming.kicks-ass.netSigned-off-by:
Ingo Molnar <mingo@kernel.org> [bwh: Backported to 3.2: - Use ACCESS_ONCE() instead of READ_ONCE() - Test perf_event::group_flags instead of group_caps - Add the err_locked cleanup block, which we didn't need before - Adjust context] Signed-off-by:
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Peter Zijlstra authored
commit 13005627 upstream. In case of: err_file: fput(event_file), we'll end up calling perf_release() which in turn will free the event. Do not then free the event _again_. Tested-by:
Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by:
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Peter Zijlstra authored
commit f63a8daa upstream. There have been a few reported issues wrt. the lack of locking around changing event->ctx. This patch tries to address those. It avoids the whole rwsem thing; and while it appears to work, please give it some thought in review. What I did fail at is sensible runtime checks on the use of event->ctx, the RCU use makes it very hard. Signed-off-by:
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Paul Bolle authored
commit 5cd3f5af upstream. Since commit c9a49628 ("nfsd: make client_lock per net") compiling nfs4state.o without CONFIG_LOCKDEP set, triggers this GCC warning: fs/nfsd/nfs4state.c: In function ‘free_client’: fs/nfsd/nfs4state.c:1051:19: warning: unused variable ‘nn’ [-Wunused-variable] The cause of that warning is that lockdep_assert_held() compiles away if CONFIG_LOCKDEP is not set. Silence this warning by using the argument to lockdep_assert_held() as a nop if CONFIG_LOCKDEP is not set. Signed-off-by:
Paul Bolle <pebolle@tiscali.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stanislav Kinsbursky <skinsbursky@parallels.com> Cc: J. Bruce Fields <bfields@redhat.com> Link: http://lkml.kernel.org/r/1359060797.1325.33.camel@x61.thuisdomeinSigned-off-by:
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Michael Ellerman authored
commit 724b6daa upstream. In perf_event_for_each() we call a function on an event, and then iterate over the siblings of the event. However we don't call the function on the siblings, we call it repeatedly on the original event - it seems "obvious" that we should be calling it with sibling as the argument. It looks like this broke in commit 75f937f2 ("Fix ctx->mutex vs counter->mutex inversion"). The only effect of the bug is that the PERF_IOC_FLAG_GROUP parameter to the ioctls doesn't work. Signed-off-by:
Michael Ellerman <michael@ellerman.id.au> Signed-off-by:
Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1334109253-31329-1-git-send-email-michael@ellerman.id.auSigned-off-by:
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Peter Hurley authored
commit dd42bf11 upstream. Line discipline drivers may mistakenly misuse ldisc-related fields when initializing. For example, a failure to initialize tty->receive_room in the N_GIGASET_M101 line discipline was recently found and fixed [1]. Now, the N_X25 line discipline has been discovered accessing the previous line discipline's already-freed private data [2]. Harden the ldisc interface against misuse by initializing revelant tty fields before instancing the new line discipline. [1] commit fd98e941 Author: Tilman Schmidt <tilman@imap.cc> Date: Tue Jul 14 00:37:13 2015 +0200 isdn/gigaset: reset tty->receive_room when attaching ser_gigaset [2] Report from Sasha Levin <sasha.levin@oracle.com> [ 634.336761] ================================================================== [ 634.338226] BUG: KASAN: use-after-free in x25_asy_open_tty+0x13d/0x490 at addr ffff8800a743efd0 [ 634.339558] Read of size 4 by task syzkaller_execu/8981 [ 634.340359] ============================================================================= [ 634.341598] BUG kmalloc-512 (Not tainted): kasan: bad access detected ... [ 634.405018] Call Trace: [ 634.405277] dump_stack (lib/dump_stack.c:52) [ 634.405775] print_trailer (mm/slub.c:655) [ 634.406361] object_err (mm/slub.c:662) [ 634.406824] kasan_report_error (mm/kasan/report.c:138 mm/kasan/report.c:236) [ 634.409581] __asan_report_load4_noabort (mm/kasan/report.c:279) [ 634.411355] x25_asy_open_tty (drivers/net/wan/x25_asy.c:559 (discriminator 1)) [ 634.413997] tty_ldisc_open.isra.2 (drivers/tty/tty_ldisc.c:447) [ 634.414549] tty_set_ldisc (drivers/tty/tty_ldisc.c:567) [ 634.415057] tty_ioctl (drivers/tty/tty_io.c:2646 drivers/tty/tty_io.c:2879) [ 634.423524] do_vfs_ioctl (fs/ioctl.c:43 fs/ioctl.c:607) [ 634.427491] SyS_ioctl (fs/ioctl.c:622 fs/ioctl.c:613) [ 634.427945] entry_SYSCALL_64_fastpath (arch/x86/entry/entry_64.S:188) Cc: Tilman Schmidt <tilman@imap.cc> Cc: Sasha Levin <sasha.levin@oracle.com> Signed-off-by:
Peter Hurley <peter@hurleysoftware.com> Signed-off-by:
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Tilman Schmidt authored
commit fd98e941 upstream. Commit 79901317 ("n_tty: Don't flush buffer when closing ldisc"), first merged in kernel release 3.10, caused the following regression in the Gigaset M101 driver: Before that commit, when closing the N_TTY line discipline in preparation to switching to N_GIGASET_M101, receive_room would be reset to a non-zero value by the call to n_tty_flush_buffer() in n_tty's close method. With the removal of that call, receive_room might be left at zero, blocking data reception on the serial line. The present patch fixes that regression by setting receive_room to an appropriate value in the ldisc open method. Fixes: 79901317 ("n_tty: Don't flush buffer when closing ldisc") Signed-off-by:
Tilman Schmidt <tilman@imap.cc> Signed-off-by:
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Peter Zijlstra authored
commit 12ca6ad2 upstream. There's a race on CPU unplug where we free the swevent hash array while it can still have events on. This will result in a use-after-free which is BAD. Simply do not free the hash array on unplug. This leaves the thing around and no use-after-free takes place. When the last swevent dies, we do a for_each_possible_cpu() iteration anyway to clean these up, at which time we'll free it, so no leakage will occur. Reported-by:
Sasha Levin <sasha.levin@oracle.com> Tested-by:
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Calvin Owens authored
commit f3951a37 upstream. In sg_common_write(), we free the block request and return -ENODEV if the device is detached in the middle of the SG_IO ioctl(). Unfortunately, sg_finish_rem_req() also tries to free srp->rq, so we end up freeing rq->cmd in the already free rq object, and then free the object itself out from under the current user. This ends up corrupting random memory via the list_head on the rq object. The most common crash trace I saw is this: ------------[ cut here ]------------ kernel BUG at block/blk-core.c:1420! Call Trace: [<ffffffff81281eab>] blk_put_request+0x5b/0x80 [<ffffffffa0069e5b>] sg_finish_rem_req+0x6b/0x120 [sg] [<ffffffffa006bcb9>] sg_common_write.isra.14+0x459/0x5a0 [sg] [<ffffffff8125b328>] ? selinux_file_alloc_security+0x48/0x70 [<ffffffffa006bf95>] sg_new_write.isra.17+0x195/0x2d0 [sg] [<ffffffffa006cef4>] sg_ioctl+0x644/0xdb0 [sg] [<ffffffff81170f80>] do_vfs_ioctl+0x90/0x520 [<ffffffff81258967>] ? file_has_perm+0x97/0xb0 [<ffffffff811714a1>] SyS_ioctl+0x91/0xb0 [<ffffffff81602afb>] tracesys+0xdd/0xe2 RIP [<ffffffff81281e04>] __blk_put_request+0x154/0x1a0 The solution is straightforward: just set srp->rq to NULL in the failure branch so that sg_finish_rem_req() doesn't attempt to re-free it. Additionally, since sg_rq_end_io() will never be called on the object when this happens, we need to free memory backing ->cmd if it isn't embedded in the object itself. KASAN was extremely helpful in finding the root cause of this bug. Signed-off-by:
Calvin Owens <calvinowens@fb.com> Acked-by:
Douglas Gilbert <dgilbert@interlog.com> Signed-off-by:
Martin K. Petersen <martin.petersen@oracle.com> [bwh: Backported to 3.2: - sg_finish_rem_req() would not free srp->rq->cmd so don't do it here either - Adjust context] Signed-off-by:
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Dan Carpenter authored
commit c88e739b upstream. These structs have holes and reserved struct members which aren't cleared. I've added a memset() so we don't leak stack information. Signed-off-by:
Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by:
Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by:
Mauro Carvalho Chehab <mchehab@redhat.com> Signed-off-by:
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Russell King authored
commit 0ea1ec71 upstream. DMA mapping permissions were being derived from pgprot_kernel directly without using PAGE_KERNEL. This causes them to be marked with executable permission, which is not what we want. Fix this. Signed-off-by:
Russell King <rmk+kernel@arm.linux.org.uk> [bwh: Backported to 3.2: adjust context] Signed-off-by:
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Eric Dumazet authored
commit 82981930 upstream. Use min_t()/max_t() macros, reformat two comments, use !!test_bit() to match !!sock_flag() Signed-off-by:
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Dan Carpenter authored
commit 93a97c50 upstream. If we can't allocate the resources in gigaset_initdriver() then we should return -ENOMEM instead of zero. Fixes: 2869b23e ("[PATCH] drivers/isdn/gigaset: new M101 driver (v2)") Signed-off-by:
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Marc Kleine-Budde authored
commit 332b05ca upstream. This patch adds a check to limit the number of can_filters that can be set via setsockopt on CAN_RAW sockets. Otherwise allocations > MAX_ORDER are not prevented resulting in a warning. Reference: https://lkml.org/lkml/2016/12/2/230Reported-by:
Marc Kleine-Budde <mkl@pengutronix.de> [bwh: Backported to 3.2: adjust filename] Signed-off-by:
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Miklos Szeredi authored
commit c01638f5 upstream. Basically, the pjdfstests set the ownership of a file to 06555, and then chowns it (as root) to a new uid/gid. Prior to commit a09f99ed ("fuse: fix killing s[ug]id in setattr"), fuse would send down a setattr with both the uid/gid change and a new mode. Now, it just sends down the uid/gid change. Technically this is NOTABUG, since POSIX doesn't _require_ that we clear these bits for a privileged process, but Linux (wisely) has done that and I think we don't want to change that behavior here. This is caused by the use of should_remove_suid(), which will always return 0 when the process has CAP_FSETID. In fact we really don't need to be calling should_remove_suid() at all, since we've already been indicated that we should remove the suid, we just don't want to use a (very) stale mode for that. This patch should fix the above as well as simplify the logic. Reported-by:
Jeff Layton <jlayton@redhat.com> Signed-off-by:
Miklos Szeredi <mszeredi@redhat.com> Fixes: a09f99ed ("fuse: fix killing s[ug]id in setattr") Reviewed-by:
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Florian Fainelli authored
commit c823abac upstream. When we unload the ep93xx_eth, whether we have opened the network interface or not, we will either hit a kernel paging request error, or a simple NULL pointer de-reference because: - if ep93xx_open has been called, we have created a valid DMA mapping for ep->descs, when we call ep93xx_stop, we also call ep93xx_free_buffers, ep->descs now has a stale value - if ep93xx_open has not been called, we have a NULL pointer for ep->descs, so performing any operation against that address just won't work Fix this by adding a NULL pointer check for ep->descs which means that ep93xx_free_buffers() was able to successfully tear down the descriptors and free the DMA cookie as well. Fixes: 1d22e05d ("[PATCH] Cirrus Logic ep93xx ethernet driver") Signed-off-by:
Florian Fainelli <f.fainelli@gmail.com> Signed-off-by:
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Kees Cook authored
commit 0eab121e upstream. Prior to commit c0371da6 ("put iov_iter into msghdr") in v3.19, there was no check that the iovec contained enough bytes for an ICMP header, and the read loop would walk across neighboring stack contents. Since the iov_iter conversion, bad arguments are noticed, but the returned error is EFAULT. Returning EINVAL is a clearer error and also solves the problem prior to v3.19. This was found using trinity with KASAN on v3.18: BUG: KASAN: stack-out-of-bounds in memcpy_fromiovec+0x60/0x114 at addr ffffffc071077da0 Read of size 8 by task trinity-c2/9623 page:ffffffbe034b9a08 count:0 mapcount:0 mapping: (null) index:0x0 flags: 0x0() page dumped because: kasan: bad access detected CPU: 0 PID: 9623 Comm: trinity-c2 Tainted: G BU 3.18.0-dirty #15 Hardware name: Google Tegra210 Smaug Rev 1,3+ (DT) Call trace: [<ffffffc000209c98>] dump_backtrace+0x0/0x1ac arch/arm64/kernel/traps.c:90 [<ffffffc000209e54>] show_stack+0x10/0x1c arch/arm64/kernel/traps.c:171 [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffc000f18dc4>] dump_stack+0x7c/0xd0 lib/dump_stack.c:50 [< inline >] print_address_description mm/kasan/report.c:147 [< inline >] kasan_report_error mm/kasan/report.c:236 [<ffffffc000373dcc>] kasan_report+0x380/0x4b8 mm/kasan/report.c:259 [< inline >] check_memory_region mm/kasan/kasan.c:264 [<ffffffc00037352c>] __asan_load8+0x20/0x70 mm/kasan/kasan.c:507 [<ffffffc0005b9624>] memcpy_fromiovec+0x5c/0x114 lib/iovec.c:15 [< inline >] memcpy_from_msg include/linux/skbuff.h:2667 [<ffffffc000ddeba0>] ping_common_sendmsg+0x50/0x108 net/ipv4/ping.c:674 [<ffffffc000dded30>] ping_v4_sendmsg+0xd8/0x698 net/ipv4/ping.c:714 [<ffffffc000dc91dc>] inet_sendmsg+0xe0/0x12c net/ipv4/af_inet.c:749 [< inline >] __sock_sendmsg_nosec net/socket.c:624 [< inline >] __sock_sendmsg net/socket.c:632 [<ffffffc000cab61c>] sock_sendmsg+0x124/0x164 net/socket.c:643 [< inline >] SYSC_sendto net/socket.c:1797 [<ffffffc000cad270>] SyS_sendto+0x178/0x1d8 net/socket.c:1761 CVE-2016-8399 Reported-by:
Qidan He <i@flanker017.me> Fixes: c319b4d7 ("net: ipv4: add IPPROTO_ICMP socket kind") Signed-off-by:
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Michal Kubeček authored
commit 3de81b75 upstream. Qian Zhang (张谦) reported a potential socket buffer overflow in tipc_msg_build() which is also known as CVE-2016-8632: due to insufficient checks, a buffer overflow can occur if MTU is too short for even tipc headers. As anyone can set device MTU in a user/net namespace, this issue can be abused by a regular user. As agreed in the discussion on Ben Hutchings' original patch, we should check the MTU at the moment a bearer is attached rather than for each processed packet. We also need to repeat the check when bearer MTU is adjusted to new device MTU. UDP case also needs a check to avoid overflow when calculating bearer MTU. Fixes: b97bf3fd ("[TIPC] Initial merge") Signed-off-by:
Michal Kubecek <mkubecek@suse.cz> Reported-by:
Qian Zhang (张谦) <zhangqian-c@360.cn> Acked-by:
Ying Xue <ying.xue@windriver.com> Signed-off-by:
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Philip Pettersson authored
commit 84ac7260 upstream. When packet_set_ring creates a ring buffer it will initialize a struct timer_list if the packet version is TPACKET_V3. This value can then be raced by a different thread calling setsockopt to set the version to TPACKET_V1 before packet_set_ring has finished. This leads to a use-after-free on a function pointer in the struct timer_list when the socket is closed as the previously initialized timer will not be deleted. The bug is fixed by taking lock_sock(sk) in packet_setsockopt when changing the packet version while also taking the lock at the start of packet_set_ring. Fixes: f6fb8f10 ("af-packet: TPACKET_V3 flexible buffer implementation.") Signed-off-by:
Philip Pettersson <philip.pettersson@gmail.com> Signed-off-by:
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Thomas Gleixner authored
commit dbb26055 upstream. David reported a futex/rtmutex state corruption. It's caused by the following problem: CPU0 CPU1 CPU2 l->owner=T1 rt_mutex_lock(l) lock(l->wait_lock) l->owner = T1 | HAS_WAITERS; enqueue(T2) boost() unlock(l->wait_lock) schedule() rt_mutex_lock(l) lock(l->wait_lock) l->owner = T1 | HAS_WAITERS; enqueue(T3) boost() unlock(l->wait_lock) schedule() signal(->T2) signal(->T3) lock(l->wait_lock) dequeue(T2) deboost() unlock(l->wait_lock) lock(l->wait_lock) dequeue(T3) ===> wait list is now empty deboost() unlock(l->wait_lock) lock(l->wait_lock) fixup_rt_mutex_waiters() if (wait_list_empty(l)) { owner = l->owner & ~HAS_WAITERS; l->owner = owner ==> l->owner = T1 } lock(l->wait_lock) rt_mutex_unlock(l) fixup_rt_mutex_waiters() if (wait_list_empty(l)) { owner = l->owner & ~HAS_WAITERS; cmpxchg(l->owner, T1, NULL) ===> Success (l->owner = NULL) l->owner = owner ==> l->owner = T1 } That means the problem is caused by fixup_rt_mutex_waiters() which does the RMW to clear the waiters bit unconditionally when there are no waiters in the rtmutexes rbtree. This can be fatal: A concurrent unlock can release the rtmutex in the fastpath because the waiters bit is not set. If the cmpxchg() gets in the middle of the RMW operation then the previous owner, which just unlocked the rtmutex is set as the owner again when the write takes place after the successfull cmpxchg(). The solution is rather trivial: verify that the owner member of the rtmutex has the waiters bit set before clearing it. This does not require a cmpxchg() or other atomic operations because the waiters bit can only be set and cleared with the rtmutex wait_lock held. It's also safe against the fast path unlock attempt. The unlock attempt via cmpxchg() will either see the bit set and take the slowpath or see the bit cleared and release it atomically in the fastpath. It's remarkable that the test program provided by David triggers on ARM64 and MIPS64 really quick, but it refuses to reproduce on x86-64, while the problem exists there as well. That refusal might explain that this got not discovered earlier despite the bug existing from day one of the rtmutex implementation more than 10 years ago. Thanks to David for meticulously instrumenting the code and providing the information which allowed to decode this subtle problem. Reported-by:
David Daney <ddaney@caviumnetworks.com> Tested-by:
David Daney <david.daney@cavium.com> Signed-off-by:
Thomas Gleixner <tglx@linutronix.de> Reviewed-by:
Steven Rostedt <rostedt@goodmis.org> Acked-by:
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Radim Krčmář authored
commit 2117d539 upstream. em_jmp_far and em_ret_far assumed that setting IP can only fail in 64 bit mode, but syzkaller proved otherwise (and SDM agrees). Code segment was restored upon failure, but it was left uninitialized outside of long mode, which could lead to a leak of host kernel stack. We could have fixed that by always saving and restoring the CS, but we take a simpler approach and just break any guest that manages to fail as the error recovery is error-prone and modern CPUs don't need emulator for this. Found by syzkaller: WARNING: CPU: 2 PID: 3668 at arch/x86/kvm/emulate.c:2217 em_ret_far+0x428/0x480 Kernel panic - not syncing: panic_on_warn set ... CPU: 2 PID: 3668 Comm: syz-executor Not tainted 4.9.0-rc4+ #49 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 [...] Call Trace: [...] __dump_stack lib/dump_stack.c:15 [...] dump_stack+0xb3/0x118 lib/dump_stack.c:51 [...] panic+0x1b7/0x3a3 kernel/panic.c:179 [...] __warn+0x1c4/0x1e0 kernel/panic.c:542 [...] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585 [...] em_ret_far+0x428/0x480 arch/x86/kvm/emulate.c:2217 [...] em_ret_far_imm+0x17/0x70 arch/x86/kvm/emulate.c:2227 [...] x86_emulate_insn+0x87a/0x3730 arch/x86/kvm/emulate.c:5294 [...] x86_emulate_instruction+0x520/0x1ba0 arch/x86/kvm/x86.c:5545 [...] emulate_instruction arch/x86/include/asm/kvm_host.h:1116 [...] complete_emulated_io arch/x86/kvm/x86.c:6870 [...] complete_emulated_mmio+0x4e9/0x710 arch/x86/kvm/x86.c:6934 [...] kvm_arch_vcpu_ioctl_run+0x3b7a/0x5a90 arch/x86/kvm/x86.c:6978 [...] kvm_vcpu_ioctl+0x61e/0xdd0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2557 [...] vfs_ioctl fs/ioctl.c:43 [...] do_vfs_ioctl+0x18c/0x1040 fs/ioctl.c:679 [...] SYSC_ioctl fs/ioctl.c:694 [...] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685 [...] entry_SYSCALL_64_fastpath+0x1f/0xc2 Reported-by:
Radim Krčmář <rkrcmar@redhat.com> [bwh: Backported to 3.2: adjust context] Signed-off-by:
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Theodore Ts'o authored
commit 8cdf3372 upstream. If the block size or cluster size is insane, reject the mount. This is important for security reasons (although we shouldn't be just depending on this check). Ref: http://www.securityfocus.com/archive/1/539661 Ref: https://bugzilla.redhat.com/show_bug.cgi?id=1332506Reported-by:
Borislav Petkov <bp@alien8.de> Reported-by:
Nikolay Borisov <kernel@kyup.com> Signed-off-by:
Theodore Ts'o <tytso@mit.edu> Signed-off-by:
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