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What happens is that a write to /dev/sg is given a request with non-zero
->iovec_count combined with zero ->dxfer_len. Or with ->dxferp pointing
to an array full of empty iovecs.
Having write permission to /dev/sg shouldn't be equivalent to the
ability to trigger BUG_ON() while holding spinlocks...
Found by Dmitry Vyukov and syzkaller.
[ The BUG_ON() got changed to a WARN_ON_ONCE(), but this fixes the
underlying issue. - Linus ]
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Don't crash the machine just because of an empty transfer. Use WARN_ON()
combined with returning an error.
Found by Dmitry Vyukov and syzkaller.
[ Changed to "WARN_ON_ONCE()". Al has a patch that should fix the root
cause, but a BUG_ON() is not acceptable in any case, and a WARN_ON()
might still be a cause of excessive log spamming.
NOTE! If this warning ever triggers, we may end up leaking resources,
since this doesn't bother to try to clean the command up. So this
WARN_ON_ONCE() triggering does imply real problems. But BUG_ON() is
much worse.
People really need to stop using BUG_ON() for "this shouldn't ever
happen". It makes pretty much any bug worse. - Linus ]
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: James Bottomley <jejb@linux.vnet.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If ip6_dst_lookup_tail has acquired a dst and fails the IPv4-mapped
check, release the dst before returning an error.
Fixes: ec5e3b0a1d41 ("ipv6: Inhibit IPv4-mapped src address on the wire.")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull ARM SoC fixes from Arnd Bergmann:
"Two more bugfixes that came in during this week:
- a defconfig change to enable a vital driver used on some Qualcomm
based phones. This was already queued for 4.11, but the maintainer
asked to have it in 4.10 after all.
- a regression fix for the reset controller framework, this got
broken by a typo in the 4.10 merge window"
* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
ARM: multi_v7_defconfig: enable Qualcomm RPMCC
reset: fix shared reset triggered_count decrement on error
Pull ARM fixes from Russell King:
"A couple of fixes from Kees concerning problems he spotted with our
user access support"
* 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm:
ARM: 8658/1: uaccess: fix zeroing of 64-bit get_user()
ARM: 8657/1: uaccess: consistently check object sizes
This patch enables the Qualcomm RPM based Clock Controller present on
A-family boards.
Signed-off-by: Andy Gross <andy.gross@linaro.org>
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Pull x86 fix from Thomas Gleixner:
"Make the build clean by working around yet another GCC stupidity"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/vm86: Fix unused variable warning if THP is disabled
The 64-bit get_user() wasn't clearing the high word due to a typo in the
error handler. The exception handler entry was already correct, though.
Noticed during recent usercopy test additions in lib/test_user_copy.c.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Pull "Reset controller fixes for v4.10" from Philipp Zabel:
- Remove erroneous negation of the error check of the reset function
to decrement trigger_count in the error case, not on success. This
fixes shared resets to actually only trigger once, as intended.
* tag 'reset-for-4.10-fixes' of https://git.pengutronix.de/git/pza/linux:
reset: fix shared reset triggered_count decrement on error
Pull locking fix from Thomas Gleixner:
"Move the futex init function to core initcall so user mode helper does
not run into an uninitialized futex syscall"
* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
futex: Move futex_init() to core_initcall
GCC complains about unused variable 'vma' in mark_screen_rdonly() if THP is
disabled:
arch/x86/kernel/vm86_32.c: In function ‘mark_screen_rdonly’:
arch/x86/kernel/vm86_32.c:180:26: warning: unused variable ‘vma’
[-Wunused-variable]
struct vm_area_struct *vma = find_vma(mm, 0xA0000);
That's silly. pmd_trans_huge() resolves to 0 when THP is disabled, so the
whole block should be eliminated.
Moving the variable declaration outside the if() block shuts GCC up.
Reported-by: Jérémy Lefaure <jeremy.lefaure@lse.epita.fr>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Tested-by: Borislav Petkov <bp@suse.de>
Cc: Carlos O'Donell <carlos@redhat.com>
Link: http://lkml.kernel.org/r/20170213125228.63645-1-kirill.shutemov@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
In commit 76624175dcae ("arm64: uaccess: consistently check object sizes"),
the object size checks are moved outside the access_ok() so that bad
destinations are detected before hitting the "memset(dest, 0, size)" in the
copy_from_user() failure path.
This makes the same change for arm, with attention given to possibly
extracting the uaccess routines into a common header file for all
architectures in the future.
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>