diff options
| author |   Tilman Schmidt <tilman@imap.cc> | 2014-10-11 13:46:30 +0200 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2014-10-14 15:05:34 -0400 |
| commit | 5510ab18048397193ae073d6b0d4ea78ff0170f5 (patch) | |
| tree | 1f78a2f37ba05126f902cd5be66c37414a4c6683 /drivers/isdn | |
| parent | isdn/capi: refactor command/subcommand table accesses (diff) | |
| download | linux-dev-5510ab18048397193ae073d6b0d4ea78ff0170f5.tar.xz linux-dev-5510ab18048397193ae073d6b0d4ea78ff0170f5.zip | |
isdn/capi: prevent NULL pointer dereference on invalid CAPI command
An invalid CAPI 2.0 command/subcommand combination may retrieve a
NULL pointer from the cpars[] array which will later be dereferenced
by the parser routines.
Fix by adding NULL pointer checks in strategic places.
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/isdn')
| -rw-r--r-- | drivers/isdn/capi/capiutil.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/isdn/capi/capiutil.c b/drivers/isdn/capi/capiutil.c index 8e401eda2aa1..36835ef3f340 100644 --- a/drivers/isdn/capi/capiutil.c +++ b/drivers/isdn/capi/capiutil.c @@ -318,6 +318,8 @@ unsigned capi_cmsg2message(_cmsg *cmsg, u8 *msg) cmsg->l = 8; cmsg->p = 0; cmsg->par = capi_cmd2par(cmsg->Command, cmsg->Subcommand); + if (!cmsg->par) + return 1; /* invalid command/subcommand */ pars_2_message(cmsg); @@ -391,6 +393,8 @@ unsigned capi_message2cmsg(_cmsg *cmsg, u8 *msg) byteTRcpy(cmsg->m + 4, &cmsg->Command); byteTRcpy(cmsg->m + 5, &cmsg->Subcommand); cmsg->par = capi_cmd2par(cmsg->Command, cmsg->Subcommand); + if (!cmsg->par) + return 1; /* invalid command/subcommand */ message_2_pars(cmsg); @@ -640,6 +644,9 @@ static _cdebbuf *printstruct(_cdebbuf *cdb, u8 *m) static _cdebbuf *protocol_message_2_pars(_cdebbuf *cdb, _cmsg *cmsg, int level) { + if (!cmsg->par) + return NULL; /* invalid command/subcommand */ + for (; TYP != _CEND; cmsg->p++) { int slen = 29 + 3 - level; int i; |