diff options
| author | Daniel Borkmann <daniel@iogearbox.net> | 2023-12-01 14:10:21 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-12-13 18:18:14 +0100 |
| commit | 148d8f0707fa9093156c6dad1ae10e7e2a9c9c1a (patch) | |
| tree | 47cba306d29174cdf20647f3a86096c694041ef3 /net/packet/internal.h | |
| parent | 965cbc6b623a84b381e73b94c20b3161c0f6f60f (diff) | |
packet: Move reference count in packet_sock to atomic_long_t
commit db3fadacaf0c817b222090290d06ca2a338422d0 upstream.
In some potential instances the reference count on struct packet_sock
could be saturated and cause overflows which gets the kernel a bit
confused. To prevent this, move to a 64-bit atomic reference count on
64-bit architectures to prevent the possibility of this type to overflow.
Because we can not handle saturation, using refcount_t is not possible
in this place. Maybe someday in the future if it changes it could be
used. Also, instead of using plain atomic64_t, use atomic_long_t instead.
32-bit machines tend to be memory-limited (i.e. anything that increases
a reference uses so much memory that you can't actually get to 2**32
references). 32-bit architectures also tend to have serious problems
with 64-bit atomics. Hence, atomic_long_t is the more natural solution.
Reported-by: "The UK's National Cyber Security Centre (NCSC)" <security@ncsc.gov.uk>
Co-developed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: stable@kernel.org
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20231201131021.19999-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/packet/internal.h')
| -rw-r--r-- | net/packet/internal.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/packet/internal.h b/net/packet/internal.h index 2b2b85dadf8e..878fcdca8c25 100644 --- a/net/packet/internal.h +++ b/net/packet/internal.h @@ -125,7 +125,7 @@ struct packet_sock { __be16 num; struct packet_rollover *rollover; struct packet_mclist *mclist; - atomic_t mapped; + atomic_long_t mapped; enum tpacket_versions tp_version; unsigned int tp_hdrlen; unsigned int tp_reserve; |