https://github.com/torvalds/linux
Revision 7c3fbbdd04a681a1992ad6a3d7a36a63ff668753 authored by Paul Mackerras on 02 December 2014, 23:59:48 UTC, committed by Linus Torvalds on 03 December 2014, 17:36:04 UTC
The bounds check for nodeid in ____cache_alloc_node gives false positives on machines where the node IDs are not contiguous, leading to a panic at boot time. For example, on a POWER8 machine the node IDs are typically 0, 1, 16 and 17. This means that num_online_nodes() returns 4, so when ____cache_alloc_node is called with nodeid = 16 the VM_BUG_ON triggers, like this: kernel BUG at /home/paulus/kernel/kvm/mm/slab.c:3079! Call Trace: .____cache_alloc_node+0x5c/0x270 (unreliable) .kmem_cache_alloc_node_trace+0xdc/0x360 .init_list+0x3c/0x128 .kmem_cache_init+0x1dc/0x258 .start_kernel+0x2a0/0x568 start_here_common+0x20/0xa8 To fix this, we instead compare the nodeid with MAX_NUMNODES, and additionally make sure it isn't negative (since nodeid is an int). The check is there mainly to protect the array dereference in the get_node() call in the next line, and the array being dereferenced is of size MAX_NUMNODES. If the nodeid is in range but invalid (for example if the node is off-line), the BUG_ON in the next line will catch that. Fixes: 14e50c6a9bc2 ("mm: slab: Verify the nodeid passed to ____cache_alloc_node") Signed-off-by: Paul Mackerras <paulus@samba.org> Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Reviewed-by: Pekka Enberg <penberg@kernel.org> Acked-by: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent b724aa2
Tip revision: 7c3fbbdd04a681a1992ad6a3d7a36a63ff668753 authored by Paul Mackerras on 02 December 2014, 23:59:48 UTC
slab: fix nodeid bounds check for non-contiguous node IDs
slab: fix nodeid bounds check for non-contiguous node IDs
Tip revision: 7c3fbbd
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arch | ||
block | ||
crypto | ||
drivers | ||
firmware | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.gitignore | -rw-r--r-- | 1.1 KB |
.mailmap | -rw-r--r-- | 4.7 KB |
COPYING | -rw-r--r-- | 18.3 KB |
CREDITS | -rw-r--r-- | 93.8 KB |
Kbuild | -rw-r--r-- | 2.5 KB |
Kconfig | -rw-r--r-- | 252 bytes |
MAINTAINERS | -rw-r--r-- | 285.4 KB |
Makefile | -rw-r--r-- | 53.2 KB |
README | -rw-r--r-- | 18.3 KB |
REPORTING-BUGS | -rw-r--r-- | 7.3 KB |
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