linux_dsm_epyc7002/arch
Thomas Gleixner 80ae7b1a91 x86/apic/vector: Prevent hlist corruption and leaks
Several people observed the WARN_ON() in irq_matrix_free() which triggers
when the caller tries to free an vector which is not in the allocation
range. Song provided the trace information which allowed to decode the root
cause.

The rework of the vector allocation mechanism failed to preserve a sanity
check, which prevents setting a new target vector/CPU when the previous
affinity change has not fully completed.

As a result a half finished affinity change can be overwritten, which can
cause the leak of a irq descriptor pointer on the previous target CPU and
double enqueue of the hlist head into the cleanup lists of two or more
CPUs. After one CPU cleaned up its vector the next CPU will invoke the
cleanup handler with vector 0, which triggers the out of range warning in
the matrix allocator.

Prevent this by checking the apic_data of the interrupt whether the
move_in_progress flag is false and the hlist node is not hashed. Return
-EBUSY if not.

This prevents the damage and restores the behaviour before the vector
allocation rework, but due to other changes in that area it also widens the
chance that user space can observe -EBUSY. In theory this should be fine,
but actually not all user space tools handle -EBUSY correctly. Addressing
that is not part of this fix, but will be addressed in follow up patches.

Fixes: 69cde0004a ("x86/vector: Use matrix allocator for vector assignment")
Reported-by: Dmitry Safonov <0x7f454c46@gmail.com>
Reported-by: Tariq Toukan <tariqt@mellanox.com>
Reported-by: Song Liu <liu.song.a23@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Song Liu <songliubraving@fb.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Cc: Mike Travis <mike.travis@hpe.com>
Cc: Borislav Petkov <bp@alien8.de>
Link: https://lkml.kernel.org/r/20180604162224.303870257@linutronix.de
2018-06-06 15:18:19 +02:00
..
alpha alpha: io: reorder barriers to guarantee writeX() and iowriteX() ordering #2 2018-05-22 18:10:36 -07:00
arc kbuild: mark $(targets) as .SECONDARY and remove .PRECIOUS markers 2018-04-07 19:04:02 +09:00
arm ARM: SoC fixes for 4.17-rc 2018-05-26 14:05:16 -07:00
arm64 ARM: SoC fixes for 4.17-rc 2018-05-26 14:05:16 -07:00
c6x c6x: pass endianness info to sparse 2018-04-10 09:58:58 -04:00
h8300
hexagon hexagon: export csum_partial_copy_nocheck 2018-05-01 15:49:50 -05:00
ia64 pci-v4.17-changes 2018-04-06 18:31:06 -07:00
m68k Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu 2018-04-09 09:15:46 -07:00
microblaze Microblaze patches for 4.17-rc1 2018-04-12 10:18:02 -07:00
mips MIPS: ptrace: Fix PTRACE_PEEKUSR requests for 64-bit FGRs 2018-05-24 14:03:14 +01:00
nds32 nds32: Fix compiler warning, Wstringop-overflow, in vdso.c 2018-05-23 13:26:22 +08:00
nios2 nios2 update for v4.17-rc1 2018-04-11 16:02:18 -07:00
openrisc OpenRISC updates for v4.17 2018-04-15 12:27:58 -07:00
parisc parisc: Move setup_profiling_timer() out of init section 2018-05-18 16:21:49 +02:00
powerpc KVM fixes for v4.17-rc7 2018-05-26 10:46:57 -07:00
riscv RISC-V: build vdso-dummy.o with -no-pie 2018-04-24 10:54:46 -07:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2018-05-30 10:30:30 -05:00
sh sh: switch to NO_BOOTMEM 2018-05-11 13:35:46 -04:00
sparc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc 2018-04-30 13:27:16 -07:00
um Merge git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml 2018-04-11 16:36:47 -07:00
unicore32 unicore32: turn flush_dcache_mmap_lock into a no-op 2018-04-11 10:28:39 -07:00
x86 x86/apic/vector: Prevent hlist corruption and leaks 2018-06-06 15:18:19 +02:00
xtensa mm: introduce MAP_FIXED_NOREPLACE 2018-04-11 10:28:38 -07:00
.gitignore
Kconfig KASAN: prohibit KASAN+STRUCTLEAK combination 2018-05-11 17:28:45 -07:00