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| author | Ben Hutchings <ben@decadent.org.uk> | 2015-11-01 16:22:53 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-11-02 16:25:00 -0500 |
| commit | 4ab42d78e37a294ac7bc56901d563c642e03c4ae (patch) | |
| tree | eed185aafd345a302f05711c3e6d5d80fca7c3f9 /drivers/net/slip/slhc.c | |
| parent | 0baa57d8dc32db78369d8b5176ef56c5e2e18ab3 (diff) | |
| download | linux-stable-4ab42d78e37a294ac7bc56901d563c642e03c4ae.tar.gz linux-stable-4ab42d78e37a294ac7bc56901d563c642e03c4ae.tar.bz2 linux-stable-4ab42d78e37a294ac7bc56901d563c642e03c4ae.zip | |
ppp, slip: Validate VJ compression slot parameters completely
Currently slhc_init() treats out-of-range values of rslots and tslots
as equivalent to 0, except that if tslots is too large it will
dereference a null pointer (CVE-2015-7799).
Add a range-check at the top of the function and make it return an
ERR_PTR() on error instead of NULL. Change the callers accordingly.
Compile-tested only.
Reported-by: 郭永刚 <guoyonggang@360.cn>
References: http://article.gmane.org/gmane.comp.security.oss.general/17908
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/slip/slhc.c')
| -rw-r--r-- | drivers/net/slip/slhc.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/drivers/net/slip/slhc.c b/drivers/net/slip/slhc.c index 079f7adfcde5..27ed25252aac 100644 --- a/drivers/net/slip/slhc.c +++ b/drivers/net/slip/slhc.c @@ -84,8 +84,9 @@ static long decode(unsigned char **cpp); static unsigned char * put16(unsigned char *cp, unsigned short x); static unsigned short pull16(unsigned char **cpp); -/* Initialize compression data structure +/* Allocate compression data structure * slots must be in range 0 to 255 (zero meaning no compression) + * Returns pointer to structure or ERR_PTR() on error. */ struct slcompress * slhc_init(int rslots, int tslots) @@ -94,11 +95,14 @@ slhc_init(int rslots, int tslots) register struct cstate *ts; struct slcompress *comp; + if (rslots < 0 || rslots > 255 || tslots < 0 || tslots > 255) + return ERR_PTR(-EINVAL); + comp = kzalloc(sizeof(struct slcompress), GFP_KERNEL); if (! comp) goto out_fail; - if ( rslots > 0 && rslots < 256 ) { + if (rslots > 0) { size_t rsize = rslots * sizeof(struct cstate); comp->rstate = kzalloc(rsize, GFP_KERNEL); if (! comp->rstate) @@ -106,7 +110,7 @@ slhc_init(int rslots, int tslots) comp->rslot_limit = rslots - 1; } - if ( tslots > 0 && tslots < 256 ) { + if (tslots > 0) { size_t tsize = tslots * sizeof(struct cstate); comp->tstate = kzalloc(tsize, GFP_KERNEL); if (! comp->tstate) @@ -141,7 +145,7 @@ out_free2: out_free: kfree(comp); out_fail: - return NULL; + return ERR_PTR(-ENOMEM); } |