linux-stable.git/kernel/bpf/syscall.c, branch v4.14.166 Linux kernel stable tree bpf: drop refcount if bpf_map_new_fd() fails in map_create() 2019-12-05T14:38:00+00:00 Peng Sun sironhide0null@gmail.com 2019-02-27T14:36:25+00:00 ebf233fd40bfc70e53ac9ba6b46ec7b3439c3da1 [ Upstream commit 352d20d611414715353ee65fc206ee57ab1a6984 ] In bpf/syscall.c, map_create() first set map->usercnt to 1, a file descriptor is supposed to return to userspace. When bpf_map_new_fd() fails, drop the refcount. Fixes: bd5f5f4ecb78 ("bpf: Add BPF_MAP_GET_FD_BY_ID") Signed-off-by: Peng Sun <sironhide0null@gmail.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 352d20d611414715353ee65fc206ee57ab1a6984 ]

In bpf/syscall.c, map_create() first set map->usercnt to 1, a file
descriptor is supposed to return to userspace. When bpf_map_new_fd()
fails, drop the refcount.

Fixes: bd5f5f4ecb78 ("bpf: Add BPF_MAP_GET_FD_BY_ID")
Signed-off-by: Peng Sun <sironhide0null@gmail.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
bpf: decrease usercnt if bpf_map_new_fd() fails in bpf_map_get_fd_by_id() 2019-12-05T14:37:58+00:00 Peng Sun sironhide0null@gmail.com 2019-02-26T14:15:37+00:00 7e50f6c7dc3006d3f92d668b61b2e75bec793ccf [ Upstream commit 781e62823cb81b972dc8652c1827205cda2ac9ac ] In bpf/syscall.c, bpf_map_get_fd_by_id() use bpf_map_inc_not_zero() to increase the refcount, both map->refcnt and map->usercnt. Then, if bpf_map_new_fd() fails, should handle map->usercnt too. Fixes: bd5f5f4ecb78 ("bpf: Add BPF_MAP_GET_FD_BY_ID") Signed-off-by: Peng Sun <sironhide0null@gmail.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 781e62823cb81b972dc8652c1827205cda2ac9ac ]

In bpf/syscall.c, bpf_map_get_fd_by_id() use bpf_map_inc_not_zero()
to increase the refcount, both map->refcnt and map->usercnt. Then, if
bpf_map_new_fd() fails, should handle map->usercnt too.

Fixes: bd5f5f4ecb78 ("bpf: Add BPF_MAP_GET_FD_BY_ID")
Signed-off-by: Peng Sun <sironhide0null@gmail.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
bpf: fix use after free in prog symbol exposure 2019-10-07T16:55:15+00:00 Daniel Borkmann daniel@iogearbox.net 2019-10-04T17:41:12+00:00 47569360be87709e690e9261df738080a2f740d2 commit c751798aa224fadc5124b49eeb38fb468c0fa039 upstream. syzkaller managed to trigger the warning in bpf_jit_free() which checks via bpf_prog_kallsyms_verify_off() for potentially unlinked JITed BPF progs in kallsyms, and subsequently trips over GPF when walking kallsyms entries: [...] 8021q: adding VLAN 0 to HW filter on device batadv0 8021q: adding VLAN 0 to HW filter on device batadv0 WARNING: CPU: 0 PID: 9869 at kernel/bpf/core.c:810 bpf_jit_free+0x1e8/0x2a0 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 9869 Comm: kworker/0:7 Not tainted 5.0.0-rc8+ #1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events bpf_prog_free_deferred Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x113/0x167 lib/dump_stack.c:113 panic+0x212/0x40b kernel/panic.c:214 __warn.cold.8+0x1b/0x38 kernel/panic.c:571 report_bug+0x1a4/0x200 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:178 [inline] do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:290 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:973 RIP: 0010:bpf_jit_free+0x1e8/0x2a0 Code: 02 4c 89 e2 83 e2 07 38 d0 7f 08 84 c0 0f 85 86 00 00 00 48 ba 00 02 00 00 00 00 ad de 0f b6 43 02 49 39 d6 0f 84 5f fe ff ff <0f> 0b e9 58 fe ff ff 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 RSP: 0018:ffff888092f67cd8 EFLAGS: 00010202 RAX: 0000000000000007 RBX: ffffc90001947000 RCX: ffffffff816e9d88 RDX: dead000000000200 RSI: 0000000000000008 RDI: ffff88808769f7f0 RBP: ffff888092f67d00 R08: fffffbfff1394059 R09: fffffbfff1394058 R10: fffffbfff1394058 R11: ffffffff89ca02c7 R12: ffffc90001947002 R13: ffffc90001947020 R14: ffffffff881eca80 R15: ffff88808769f7e8 BUG: unable to handle kernel paging request at fffffbfff400d000 #PF error: [normal kernel read fault] PGD 21ffee067 P4D 21ffee067 PUD 21ffed067 PMD 9f942067 PTE 0 Oops: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 9869 Comm: kworker/0:7 Not tainted 5.0.0-rc8+ #1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events bpf_prog_free_deferred RIP: 0010:bpf_get_prog_addr_region kernel/bpf/core.c:495 [inline] RIP: 0010:bpf_tree_comp kernel/bpf/core.c:558 [inline] RIP: 0010:__lt_find include/linux/rbtree_latch.h:115 [inline] RIP: 0010:latch_tree_find include/linux/rbtree_latch.h:208 [inline] RIP: 0010:bpf_prog_kallsyms_find+0x107/0x2e0 kernel/bpf/core.c:632 Code: 00 f0 ff ff 44 38 c8 7f 08 84 c0 0f 85 fa 00 00 00 41 f6 45 02 01 75 02 0f 0b 48 39 da 0f 82 92 00 00 00 48 89 d8 48 c1 e8 03 <42> 0f b6 04 30 84 c0 74 08 3c 03 0f 8e 45 01 00 00 8b 03 48 c1 e0 [...] Upon further debugging, it turns out that whenever we trigger this issue, the kallsyms removal in bpf_prog_ksym_node_del() was /skipped/ but yet bpf_jit_free() reported that the entry is /in use/. Problem is that symbol exposure via bpf_prog_kallsyms_add() but also perf_event_bpf_event() were done /after/ bpf_prog_new_fd(). Once the fd is exposed to the public, a parallel close request came in right before we attempted to do the bpf_prog_kallsyms_add(). Given at this time the prog reference count is one, we start to rip everything underneath us via bpf_prog_release() -> bpf_prog_put(). The memory is eventually released via deferred free, so we're seeing that bpf_jit_free() has a kallsym entry because we added it from bpf_prog_load() but /after/ bpf_prog_put() from the remote CPU. Therefore, move both notifications /before/ we install the fd. The issue was never seen between bpf_prog_alloc_id() and bpf_prog_new_fd() because upon bpf_prog_get_fd_by_id() we'll take another reference to the BPF prog, so we're still holding the original reference from the bpf_prog_load(). Fixes: 6ee52e2a3fe4 ("perf, bpf: Introduce PERF_RECORD_BPF_EVENT") Fixes: 74451e66d516 ("bpf: make jited programs visible in traces") Reported-by: syzbot+bd3bba6ff3fcea7a6ec6@syzkaller.appspotmail.com Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Song Liu <songliubraving@fb.com> Signed-off-by: Zubin Mithra <zsm@chromium.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
commit c751798aa224fadc5124b49eeb38fb468c0fa039 upstream.

syzkaller managed to trigger the warning in bpf_jit_free() which checks via
bpf_prog_kallsyms_verify_off() for potentially unlinked JITed BPF progs
in kallsyms, and subsequently trips over GPF when walking kallsyms entries:

  [...]
  8021q: adding VLAN 0 to HW filter on device batadv0
  8021q: adding VLAN 0 to HW filter on device batadv0
  WARNING: CPU: 0 PID: 9869 at kernel/bpf/core.c:810 bpf_jit_free+0x1e8/0x2a0
  Kernel panic - not syncing: panic_on_warn set ...
  CPU: 0 PID: 9869 Comm: kworker/0:7 Not tainted 5.0.0-rc8+ #1
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
  Workqueue: events bpf_prog_free_deferred
  Call Trace:
   __dump_stack lib/dump_stack.c:77 [inline]
   dump_stack+0x113/0x167 lib/dump_stack.c:113
   panic+0x212/0x40b kernel/panic.c:214
   __warn.cold.8+0x1b/0x38 kernel/panic.c:571
   report_bug+0x1a4/0x200 lib/bug.c:186
   fixup_bug arch/x86/kernel/traps.c:178 [inline]
   do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271
   do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:290
   invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:973
  RIP: 0010:bpf_jit_free+0x1e8/0x2a0
  Code: 02 4c 89 e2 83 e2 07 38 d0 7f 08 84 c0 0f 85 86 00 00 00 48 ba 00 02 00 00 00 00 ad de 0f b6 43 02 49 39 d6 0f 84 5f fe ff ff <0f> 0b e9 58 fe ff ff 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1
  RSP: 0018:ffff888092f67cd8 EFLAGS: 00010202
  RAX: 0000000000000007 RBX: ffffc90001947000 RCX: ffffffff816e9d88
  RDX: dead000000000200 RSI: 0000000000000008 RDI: ffff88808769f7f0
  RBP: ffff888092f67d00 R08: fffffbfff1394059 R09: fffffbfff1394058
  R10: fffffbfff1394058 R11: ffffffff89ca02c7 R12: ffffc90001947002
  R13: ffffc90001947020 R14: ffffffff881eca80 R15: ffff88808769f7e8
  BUG: unable to handle kernel paging request at fffffbfff400d000
  #PF error: [normal kernel read fault]
  PGD 21ffee067 P4D 21ffee067 PUD 21ffed067 PMD 9f942067 PTE 0
  Oops: 0000 [#1] PREEMPT SMP KASAN
  CPU: 0 PID: 9869 Comm: kworker/0:7 Not tainted 5.0.0-rc8+ #1
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
  Workqueue: events bpf_prog_free_deferred
  RIP: 0010:bpf_get_prog_addr_region kernel/bpf/core.c:495 [inline]
  RIP: 0010:bpf_tree_comp kernel/bpf/core.c:558 [inline]
  RIP: 0010:__lt_find include/linux/rbtree_latch.h:115 [inline]
  RIP: 0010:latch_tree_find include/linux/rbtree_latch.h:208 [inline]
  RIP: 0010:bpf_prog_kallsyms_find+0x107/0x2e0 kernel/bpf/core.c:632
  Code: 00 f0 ff ff 44 38 c8 7f 08 84 c0 0f 85 fa 00 00 00 41 f6 45 02 01 75 02 0f 0b 48 39 da 0f 82 92 00 00 00 48 89 d8 48 c1 e8 03 <42> 0f b6 04 30 84 c0 74 08 3c 03 0f 8e 45 01 00 00 8b 03 48 c1 e0
  [...]

Upon further debugging, it turns out that whenever we trigger this
issue, the kallsyms removal in bpf_prog_ksym_node_del() was /skipped/
but yet bpf_jit_free() reported that the entry is /in use/.

Problem is that symbol exposure via bpf_prog_kallsyms_add() but also
perf_event_bpf_event() were done /after/ bpf_prog_new_fd(). Once the
fd is exposed to the public, a parallel close request came in right
before we attempted to do the bpf_prog_kallsyms_add().

Given at this time the prog reference count is one, we start to rip
everything underneath us via bpf_prog_release() -> bpf_prog_put().
The memory is eventually released via deferred free, so we're seeing
that bpf_jit_free() has a kallsym entry because we added it from
bpf_prog_load() but /after/ bpf_prog_put() from the remote CPU.

Therefore, move both notifications /before/ we install the fd. The
issue was never seen between bpf_prog_alloc_id() and bpf_prog_new_fd()
because upon bpf_prog_get_fd_by_id() we'll take another reference to
the BPF prog, so we're still holding the original reference from the
bpf_prog_load().

Fixes: 6ee52e2a3fe4 ("perf, bpf: Introduce PERF_RECORD_BPF_EVENT")
Fixes: 74451e66d516 ("bpf: make jited programs visible in traces")
Reported-by: syzbot+bd3bba6ff3fcea7a6ec6@syzkaller.appspotmail.com
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Song Liu <songliubraving@fb.com>
Signed-off-by: Zubin Mithra <zsm@chromium.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
bpf: add map_lookup_elem_sys_only for lookups from syscall side 2019-05-25T16:25:37+00:00 Daniel Borkmann daniel@iogearbox.net 2019-05-13T23:18:55+00:00 9f2292309de82d53b03123e7991912150a8016d4 commit c6110222c6f49ea68169f353565eb865488a8619 upstream. Add a callback map_lookup_elem_sys_only() that map implementations could use over map_lookup_elem() from system call side in case the map implementation needs to handle the latter differently than from the BPF data path. If map_lookup_elem_sys_only() is set, this will be preferred pick for map lookups out of user space. This hook is used in a follow-up fix for LRU map, but once development window opens, we can convert other map types from map_lookup_elem() (here, the one called upon BPF_MAP_LOOKUP_ELEM cmd is meant) over to use the callback to simplify and clean up the latter. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit c6110222c6f49ea68169f353565eb865488a8619 upstream.

Add a callback map_lookup_elem_sys_only() that map implementations
could use over map_lookup_elem() from system call side in case the
map implementation needs to handle the latter differently than from
the BPF data path. If map_lookup_elem_sys_only() is set, this will
be preferred pick for map lookups out of user space. This hook is
used in a follow-up fix for LRU map, but once development window
opens, we can convert other map types from map_lookup_elem() (here,
the one called upon BPF_MAP_LOOKUP_ELEM cmd is meant) over to use
the callback to simplify and clean up the latter.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bpf: wait for running BPF programs when updating map-in-map 2018-11-13T19:15:18+00:00 Daniel Colascione dancol@google.com 2018-10-12T10:54:27+00:00 4bea15f7933dc87a091a7481590dd2ea1088b2bf commit 1ae80cf31938c8f77c37a29bbe29e7f1cd492be8 upstream. The map-in-map frequently serves as a mechanism for atomic snapshotting of state that a BPF program might record. The current implementation is dangerous to use in this way, however, since userspace has no way of knowing when all programs that might have retrieved the "old" value of the map may have completed. This change ensures that map update operations on map-in-map map types always wait for all references to the old map to drop before returning to userspace. Signed-off-by: Daniel Colascione <dancol@google.com> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> [fengc@google.com: 4.14 backport: adjust context] Signed-off-by: Chenbo Feng <fengc@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 1ae80cf31938c8f77c37a29bbe29e7f1cd492be8 upstream.

The map-in-map frequently serves as a mechanism for atomic
snapshotting of state that a BPF program might record.  The current
implementation is dangerous to use in this way, however, since
userspace has no way of knowing when all programs that might have
retrieved the "old" value of the map may have completed.

This change ensures that map update operations on map-in-map map types
always wait for all references to the old map to drop before returning
to userspace.

Signed-off-by: Daniel Colascione <dancol@google.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
[fengc@google.com: 4.14 backport: adjust context]
Signed-off-by: Chenbo Feng <fengc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bpf: sockmap, map_release does not hold refcnt for pinned maps 2018-11-04T13:52:44+00:00 John Fastabend john.fastabend@gmail.com 2018-04-23T22:39:23+00:00 3c0cff34e91e4ea1fdf74df65db98ee455190dfa [ Upstream commit ba6b8de423f8d0dee48d6030288ed81c03ddf9f0 ] Relying on map_release hook to decrement the reference counts when a map is removed only works if the map is not being pinned. In the pinned case the ref is decremented immediately and the BPF programs released. After this BPF programs may not be in-use which is not what the user would expect. This patch moves the release logic into bpf_map_put_uref() and brings sockmap in-line with how a similar case is handled in prog array maps. Fixes: 3d9e952697de ("bpf: sockmap, fix leaking maps with attached but not detached progs") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit ba6b8de423f8d0dee48d6030288ed81c03ddf9f0 ]

Relying on map_release hook to decrement the reference counts when a
map is removed only works if the map is not being pinned. In the
pinned case the ref is decremented immediately and the BPF programs
released. After this BPF programs may not be in-use which is not
what the user would expect.

This patch moves the release logic into bpf_map_put_uref() and brings
sockmap in-line with how a similar case is handled in prog array maps.

Fixes: 3d9e952697de ("bpf: sockmap, fix leaking maps with attached but not detached progs")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
bpf: skip unnecessary capability check 2018-03-28T16:24:50+00:00 Chenbo Feng fengc@google.com 2018-03-20T00:57:27+00:00 b4e02202a0ba47d7ba546ae681f66ed68e69d459 commit 0fa4fe85f4724fff89b09741c437cbee9cf8b008 upstream. The current check statement in BPF syscall will do a capability check for CAP_SYS_ADMIN before checking sysctl_unprivileged_bpf_disabled. This code path will trigger unnecessary security hooks on capability checking and cause false alarms on unprivileged process trying to get CAP_SYS_ADMIN access. This can be resolved by simply switch the order of the statement and CAP_SYS_ADMIN is not required anyway if unprivileged bpf syscall is allowed. Signed-off-by: Chenbo Feng <fengc@google.com> Acked-by: Lorenzo Colitti <lorenzo@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 0fa4fe85f4724fff89b09741c437cbee9cf8b008 upstream.

The current check statement in BPF syscall will do a capability check
for CAP_SYS_ADMIN before checking sysctl_unprivileged_bpf_disabled. This
code path will trigger unnecessary security hooks on capability checking
and cause false alarms on unprivileged process trying to get CAP_SYS_ADMIN
access. This can be resolved by simply switch the order of the statement
and CAP_SYS_ADMIN is not required anyway if unprivileged bpf syscall is
allowed.

Signed-off-by: Chenbo Feng <fengc@google.com>
Acked-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bpf: do not disable/enable BH in bpf_map_free_id() 2017-09-19T22:42:54+00:00 Eric Dumazet edumazet@google.com 2017-09-19T16:15:59+00:00 930651a75bf1ba6893a8b8475270664ebdb6cf4a syzkaller reported following splat [1] Since hard irq are disabled by the caller, bpf_map_free_id() should not try to enable/disable BH. Another solution would be to change htab_map_delete_elem() to defer the free_htab_elem() call after raw_spin_unlock_irqrestore(&b->lock, flags), but this might be not enough to cover other code paths. [1] WARNING: CPU: 1 PID: 8052 at kernel/softirq.c:161 __local_bh_enable_ip +0x1e/0x160 kernel/softirq.c:161 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 8052 Comm: syz-executor1 Not tainted 4.13.0-next-20170915+ #23 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 panic+0x1e4/0x417 kernel/panic.c:181 __warn+0x1c4/0x1d9 kernel/panic.c:542 report_bug+0x211/0x2d0 lib/bug.c:183 fixup_bug+0x40/0x90 arch/x86/kernel/traps.c:178 do_trap_no_signal arch/x86/kernel/traps.c:212 [inline] do_trap+0x260/0x390 arch/x86/kernel/traps.c:261 do_error_trap+0x120/0x390 arch/x86/kernel/traps.c:298 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:311 invalid_op+0x18/0x20 arch/x86/entry/entry_64.S:905 RIP: 0010:__local_bh_enable_ip+0x1e/0x160 kernel/softirq.c:161 RSP: 0018:ffff8801cdcd7748 EFLAGS: 00010046 RAX: 0000000000000082 RBX: 0000000000000201 RCX: 0000000000000000 RDX: 1ffffffff0b5933c RSI: 0000000000000201 RDI: ffffffff85ac99e0 RBP: ffff8801cdcd7758 R08: ffffffff85b87158 R09: 1ffff10039b9aec6 R10: ffff8801c99f24c0 R11: 0000000000000002 R12: ffffffff817b0b47 R13: dffffc0000000000 R14: ffff8801cdcd77e8 R15: 0000000000000001 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:176 [inline] _raw_spin_unlock_bh+0x30/0x40 kernel/locking/spinlock.c:207 spin_unlock_bh include/linux/spinlock.h:361 [inline] bpf_map_free_id kernel/bpf/syscall.c:197 [inline] __bpf_map_put+0x267/0x320 kernel/bpf/syscall.c:227 bpf_map_put+0x1a/0x20 kernel/bpf/syscall.c:235 bpf_map_fd_put_ptr+0x15/0x20 kernel/bpf/map_in_map.c:96 free_htab_elem+0xc3/0x1b0 kernel/bpf/hashtab.c:658 htab_map_delete_elem+0x74d/0x970 kernel/bpf/hashtab.c:1063 map_delete_elem kernel/bpf/syscall.c:633 [inline] SYSC_bpf kernel/bpf/syscall.c:1479 [inline] SyS_bpf+0x2188/0x46a0 kernel/bpf/syscall.c:1451 entry_SYSCALL_64_fastpath+0x1f/0xbe Fixes: f3f1c054c288 ("bpf: Introduce bpf_map ID") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Martin KaFai Lau <kafai@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net> 
syzkaller reported following splat [1]

Since hard irq are disabled by the caller, bpf_map_free_id()
should not try to enable/disable BH.

Another solution would be to change htab_map_delete_elem() to
defer the free_htab_elem() call after
raw_spin_unlock_irqrestore(&b->lock, flags), but this might be not
enough to cover other code paths.

[1]
WARNING: CPU: 1 PID: 8052 at kernel/softirq.c:161 __local_bh_enable_ip
+0x1e/0x160 kernel/softirq.c:161
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 8052 Comm: syz-executor1 Not tainted 4.13.0-next-20170915+
#23
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:52
 panic+0x1e4/0x417 kernel/panic.c:181
 __warn+0x1c4/0x1d9 kernel/panic.c:542
 report_bug+0x211/0x2d0 lib/bug.c:183
 fixup_bug+0x40/0x90 arch/x86/kernel/traps.c:178
 do_trap_no_signal arch/x86/kernel/traps.c:212 [inline]
 do_trap+0x260/0x390 arch/x86/kernel/traps.c:261
 do_error_trap+0x120/0x390 arch/x86/kernel/traps.c:298
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:311
 invalid_op+0x18/0x20 arch/x86/entry/entry_64.S:905
RIP: 0010:__local_bh_enable_ip+0x1e/0x160 kernel/softirq.c:161
RSP: 0018:ffff8801cdcd7748 EFLAGS: 00010046
RAX: 0000000000000082 RBX: 0000000000000201 RCX: 0000000000000000
RDX: 1ffffffff0b5933c RSI: 0000000000000201 RDI: ffffffff85ac99e0
RBP: ffff8801cdcd7758 R08: ffffffff85b87158 R09: 1ffff10039b9aec6
R10: ffff8801c99f24c0 R11: 0000000000000002 R12: ffffffff817b0b47
R13: dffffc0000000000 R14: ffff8801cdcd77e8 R15: 0000000000000001
 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:176 [inline]
 _raw_spin_unlock_bh+0x30/0x40 kernel/locking/spinlock.c:207
 spin_unlock_bh include/linux/spinlock.h:361 [inline]
 bpf_map_free_id kernel/bpf/syscall.c:197 [inline]
 __bpf_map_put+0x267/0x320 kernel/bpf/syscall.c:227
 bpf_map_put+0x1a/0x20 kernel/bpf/syscall.c:235
 bpf_map_fd_put_ptr+0x15/0x20 kernel/bpf/map_in_map.c:96
 free_htab_elem+0xc3/0x1b0 kernel/bpf/hashtab.c:658
 htab_map_delete_elem+0x74d/0x970 kernel/bpf/hashtab.c:1063
 map_delete_elem kernel/bpf/syscall.c:633 [inline]
 SYSC_bpf kernel/bpf/syscall.c:1479 [inline]
 SyS_bpf+0x2188/0x46a0 kernel/bpf/syscall.c:1451
 entry_SYSCALL_64_fastpath+0x1f/0xbe

Fixes: f3f1c054c288 ("bpf: Introduce bpf_map ID")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
bpf: add support for sockmap detach programs 2017-09-09T04:11:00+00:00 John Fastabend john.fastabend@gmail.com 2017-09-08T21:00:49+00:00 5a67da2a71c64daeb456f6f3e87b5c7cecdc5ffa The bpf map sockmap supports adding programs via attach commands. This patch adds the detach command to keep the API symmetric and allow users to remove previously added programs. Otherwise the user would have to delete the map and re-add it to get in this state. This also adds a series of additional tests to capture detach operation and also attaching/detaching invalid prog types. API note: socks will run (or not run) programs depending on the state of the map at the time the sock is added. We do not for example walk the map and remove programs from previously attached socks. Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> 
The bpf map sockmap supports adding programs via attach commands. This
patch adds the detach command to keep the API symmetric and allow
users to remove previously added programs. Otherwise the user would
have to delete the map and re-add it to get in this state.

This also adds a series of additional tests to capture detach operation
and also attaching/detaching invalid prog types.

API note: socks will run (or not run) programs depending on the state
of the map at the time the sock is added. We do not for example walk
the map and remove programs from previously attached socks.

Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
bpf: fix numa_node validation 2017-09-05T16:10:02+00:00 Eric Dumazet edumazet@google.com 2017-09-05T05:41:02+00:00 96e5ae4e76f1ea950d493f510399b49308bea731 syzkaller reported crashes in bpf map creation or map update [1] Problem is that nr_node_ids is a signed integer, NUMA_NO_NODE is also an integer, so it is very tempting to declare numa_node as a signed integer. This means the typical test to validate a user provided value : if (numa_node != NUMA_NO_NODE && (numa_node >= nr_node_ids || !node_online(numa_node))) must be written : if (numa_node != NUMA_NO_NODE && ((unsigned int)numa_node >= nr_node_ids || !node_online(numa_node))) [1] kernel BUG at mm/slab.c:3256! invalid opcode: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 0 PID: 2946 Comm: syzkaller916108 Not tainted 4.13.0-rc7+ #35 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801d2bc60c0 task.stack: ffff8801c0c90000 RIP: 0010:____cache_alloc_node+0x1d4/0x1e0 mm/slab.c:3292 RSP: 0018:ffff8801c0c97638 EFLAGS: 00010096 RAX: ffffffffffff8b7b RBX: 0000000001080220 RCX: 0000000000000000 RDX: 00000000ffff8b7b RSI: 0000000001080220 RDI: ffff8801dac00040 RBP: ffff8801c0c976c0 R08: 0000000000000000 R09: 0000000000000000 R10: ffff8801c0c97620 R11: 0000000000000001 R12: ffff8801dac00040 R13: ffff8801dac00040 R14: 0000000000000000 R15: 00000000ffff8b7b FS: 0000000002119940(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020001fec CR3: 00000001d2980000 CR4: 00000000001406f0 Call Trace: __do_kmalloc_node mm/slab.c:3688 [inline] __kmalloc_node+0x33/0x70 mm/slab.c:3696 kmalloc_node include/linux/slab.h:535 [inline] alloc_htab_elem+0x2a8/0x480 kernel/bpf/hashtab.c:740 htab_map_update_elem+0x740/0xb80 kernel/bpf/hashtab.c:820 map_update_elem kernel/bpf/syscall.c:587 [inline] SYSC_bpf kernel/bpf/syscall.c:1468 [inline] SyS_bpf+0x20c5/0x4c40 kernel/bpf/syscall.c:1443 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x440409 RSP: 002b:00007ffd1f1792b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440409 RDX: 0000000000000020 RSI: 0000000020006000 RDI: 0000000000000002 RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401d70 R13: 0000000000401e00 R14: 0000000000000000 R15: 0000000000000000 Code: 83 c2 01 89 50 18 4c 03 70 08 e8 38 f4 ff ff 4d 85 f6 0f 85 3e ff ff ff 44 89 fe 4c 89 ef e8 94 fb ff ff 49 89 c6 e9 2b ff ff ff <0f> 0b 0f 0b 0f 0b 66 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 RIP: ____cache_alloc_node+0x1d4/0x1e0 mm/slab.c:3292 RSP: ffff8801c0c97638 ---[ end trace d745f355da2e33ce ]--- Kernel panic - not syncing: Fatal exception Fixes: 96eabe7a40aa ("bpf: Allow selecting numa node during map creation") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Martin KaFai Lau <kafai@fb.com> Cc: Alexei Starovoitov <ast@fb.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> 
syzkaller reported crashes in bpf map creation or map update [1]

Problem is that nr_node_ids is a signed integer,
NUMA_NO_NODE is also an integer, so it is very tempting
to declare numa_node as a signed integer.

This means the typical test to validate a user provided value :

        if (numa_node != NUMA_NO_NODE &&
            (numa_node >= nr_node_ids ||
             !node_online(numa_node)))

must be written :

        if (numa_node != NUMA_NO_NODE &&
            ((unsigned int)numa_node >= nr_node_ids ||
             !node_online(numa_node)))

[1]
kernel BUG at mm/slab.c:3256!
invalid opcode: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 2946 Comm: syzkaller916108 Not tainted 4.13.0-rc7+ #35
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d2bc60c0 task.stack: ffff8801c0c90000
RIP: 0010:____cache_alloc_node+0x1d4/0x1e0 mm/slab.c:3292
RSP: 0018:ffff8801c0c97638 EFLAGS: 00010096
RAX: ffffffffffff8b7b RBX: 0000000001080220 RCX: 0000000000000000
RDX: 00000000ffff8b7b RSI: 0000000001080220 RDI: ffff8801dac00040
RBP: ffff8801c0c976c0 R08: 0000000000000000 R09: 0000000000000000
R10: ffff8801c0c97620 R11: 0000000000000001 R12: ffff8801dac00040
R13: ffff8801dac00040 R14: 0000000000000000 R15: 00000000ffff8b7b
FS:  0000000002119940(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020001fec CR3: 00000001d2980000 CR4: 00000000001406f0
Call Trace:
 __do_kmalloc_node mm/slab.c:3688 [inline]
 __kmalloc_node+0x33/0x70 mm/slab.c:3696
 kmalloc_node include/linux/slab.h:535 [inline]
 alloc_htab_elem+0x2a8/0x480 kernel/bpf/hashtab.c:740
 htab_map_update_elem+0x740/0xb80 kernel/bpf/hashtab.c:820
 map_update_elem kernel/bpf/syscall.c:587 [inline]
 SYSC_bpf kernel/bpf/syscall.c:1468 [inline]
 SyS_bpf+0x20c5/0x4c40 kernel/bpf/syscall.c:1443
 entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x440409
RSP: 002b:00007ffd1f1792b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440409
RDX: 0000000000000020 RSI: 0000000020006000 RDI: 0000000000000002
RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401d70
R13: 0000000000401e00 R14: 0000000000000000 R15: 0000000000000000
Code: 83 c2 01 89 50 18 4c 03 70 08 e8 38 f4 ff ff 4d 85 f6 0f 85 3e ff ff ff 44 89 fe 4c 89 ef e8 94 fb ff ff 49 89 c6 e9 2b ff ff ff <0f> 0b 0f 0b 0f 0b 66 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41
RIP: ____cache_alloc_node+0x1d4/0x1e0 mm/slab.c:3292 RSP: ffff8801c0c97638
---[ end trace d745f355da2e33ce ]---
Kernel panic - not syncing: Fatal exception

Fixes: 96eabe7a40aa ("bpf: Allow selecting numa node during map creation")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>