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Yonghong Song 683d2ac390 bpf: fix sock hashmap kmalloc warning
syzbot reported a kernel warning below:
  WARNING: CPU: 0 PID: 4499 at mm/slab_common.c:996 kmalloc_slab+0x56/0x70 mm/slab_common.c:996
  Kernel panic - not syncing: panic_on_warn set ...

  CPU: 0 PID: 4499 Comm: syz-executor050 Not tainted 4.17.0-rc3+ #9
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
  Call Trace:
   __dump_stack lib/dump_stack.c:77 [inline]
   dump_stack+0x1b9/0x294 lib/dump_stack.c:113
   panic+0x22f/0x4de kernel/panic.c:184
   __warn.cold.8+0x163/0x1b3 kernel/panic.c:536
   report_bug+0x252/0x2d0 lib/bug.c:186
   fixup_bug arch/x86/kernel/traps.c:178 [inline]
   do_error_trap+0x1de/0x490 arch/x86/kernel/traps.c:296
   do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315
   invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:992
  RIP: 0010:kmalloc_slab+0x56/0x70 mm/slab_common.c:996
  RSP: 0018:ffff8801d907fc58 EFLAGS: 00010246
  RAX: 0000000000000000 RBX: ffff8801aeecb280 RCX: ffffffff8185ebd7
  RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000ffffffe1
  RBP: ffff8801d907fc58 R08: ffff8801adb5e1c0 R09: ffffed0035a84700
  R10: ffffed0035a84700 R11: ffff8801ad423803 R12: ffff8801aeecb280
  R13: 00000000fffffff4 R14: ffff8801ad891a00 R15: 00000000014200c0
   __do_kmalloc mm/slab.c:3713 [inline]
   __kmalloc+0x25/0x760 mm/slab.c:3727
   kmalloc include/linux/slab.h:517 [inline]
   map_get_next_key+0x24a/0x640 kernel/bpf/syscall.c:858
   __do_sys_bpf kernel/bpf/syscall.c:2131 [inline]
   __se_sys_bpf kernel/bpf/syscall.c:2096 [inline]
   __x64_sys_bpf+0x354/0x4f0 kernel/bpf/syscall.c:2096
   do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

The test case is against sock hashmap with a key size 0xffffffe1.
Such a large key size will cause the below code in function
sock_hash_alloc() overflowing and produces a smaller elem_size,
hence map creation will be successful.
    htab->elem_size = sizeof(struct htab_elem) +
                      round_up(htab->map.key_size, 8);

Later, when map_get_next_key is called and kernel tries
to allocate the key unsuccessfully, it will issue
the above warning.

Similar to hashtab, ensure the key size is at most
MAX_BPF_STACK for a successful map creation.

Fixes: 8111038444 ("bpf: sockmap, add hash map support")
Reported-by: syzbot+e4566d29080e7f3460ff@syzkaller.appspotmail.com
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-17 00:56:06 +02:00
arch bpf, arm64: save 4 bytes in prologue when ebpf insns came from cbpf 2018-05-14 19:11:45 -07:00
block Revert "blk-mq: remove code for dealing with remapping queue" 2018-04-25 09:49:22 -06:00
certs certs/blacklist_nohashes.c: fix const confusion in certs blacklist 2018-02-21 15:35:43 -08:00
crypto crypto: drbg - set freed buffers to NULL 2018-04-21 00:57:00 +08:00
Documentation bpf, doc: howto use/run the BPF selftests 2018-05-14 23:02:58 -07:00
drivers nfp: bpf: support setting the RX queue index 2018-05-09 18:04:37 +02:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs Changes since last update: 2018-05-01 09:11:45 -07:00
include bpf: add __printf verification to bpf_verifier_vlog 2018-05-17 00:49:17 +02:00
init bpf: enable stackmap with build_id in nmi context 2018-05-14 23:29:45 +02:00
ipc ipc/shm: fix use-after-free of shm file via remap_file_pages() 2018-04-13 17:10:27 -07:00
kernel bpf: fix sock hashmap kmalloc warning 2018-05-17 00:56:06 +02:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2018-05-07 23:35:08 -04:00
LICENSES LICENSES: Add MPL-1.1 license 2018-01-06 10:59:44 -07:00
mm x86/pti: Filter at vma->vm_page_prot population 2018-04-25 11:02:51 +02:00
net bpf: sockmap, add hash map support 2018-05-15 20:41:03 +02:00
samples samples/bpf: Decrement ttl in fib forwarding example 2018-05-16 22:04:52 +02:00
scripts bpf: relax constraints on formatting for eBPF helper documentation 2018-05-02 17:46:50 +02:00
security net: initial AF_XDP skeleton 2018-05-03 15:55:23 -07:00
sound ALSA: dice: fix error path to destroy initialized stream data 2018-04-26 15:24:54 +02:00
tools libbpf: add ifindex to enable offload support 2018-05-17 00:54:26 +02:00
usr kbuild: rename built-in.o to built-in.a 2018-03-26 02:01:19 +09:00
virt KVM fixes for v4.17-rc3 2018-04-27 16:13:31 -07:00
.clang-format clang-format: add configuration file 2018-04-11 10:28:35 -07:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
.mailmap Merge candidates for 4.17 merge window 2018-04-06 17:35:43 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS/CREDITS: Drop METAG ARCHITECTURE 2018-03-05 16:34:24 +00:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2018-05-07 23:35:08 -04:00
Makefile Linux v4.17-rc3 2018-04-29 14:17:42 -07:00
README Docs: Added a pointer to the formatted docs to README 2018-03-21 09:02:53 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.