| Message ID | 20240913143010.117883-1-r.smirnov@omp.ru (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v3] KEYS: prevent NULL pointer dereference in find_asymmetric_key() | expand |
On Fri Sep 13, 2024 at 5:30 PM EEST, Roman Smirnov wrote: > In find_asymmetric_key(), if all NULLs are passed in the id_{0,1,2} > arguments, the kernel will first emit WARN but then have an oops > because id_2 gets dereferenced anyway. > > Add the missing id_2 check and move WARN_ON() to the final else branch > to avoid duplicate NULL checks. > > Found by Linux Verification Center (linuxtesting.org) with Svace static > analysis tool. > > Fixes: 7d30198ee24f ("keys: X.509 public key issuer lookup without AKID") > Suggested-by: Sergey Shtylyov <s.shtylyov@omp.ru> > Signed-off-by: Roman Smirnov <r.smirnov@omp.ru> > Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru> > --- > V1 -> V2: updated patch description, returned WARN_ON() macro > V2 -> V3: updated patch description > crypto/asymmetric_keys/asymmetric_type.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c > index a5da8ccd353e..43af5fa510c0 100644 > --- a/crypto/asymmetric_keys/asymmetric_type.c > +++ b/crypto/asymmetric_keys/asymmetric_type.c > @@ -60,17 +60,18 @@ struct key *find_asymmetric_key(struct key *keyring, > char *req, *p; > int len; > > - WARN_ON(!id_0 && !id_1 && !id_2); > - > if (id_0) { > lookup = id_0->data; > len = id_0->len; > } else if (id_1) { > lookup = id_1->data; > len = id_1->len; > - } else { > + } else if (id_2) { > lookup = id_2->data; > len = id_2->len; > + } else { > + WARN_ON(1); > + return ERR_PTR(-EINVAL); > } > > /* Construct an identifier "id:<keyid>". */ Thanks this works for me at least. David do you have objections? If not, I'll pick it up for my v6.12 PR. BR, Jarkko
diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c index a5da8ccd353e..43af5fa510c0 100644 --- a/crypto/asymmetric_keys/asymmetric_type.c +++ b/crypto/asymmetric_keys/asymmetric_type.c @@ -60,17 +60,18 @@ struct key *find_asymmetric_key(struct key *keyring, char *req, *p; int len; - WARN_ON(!id_0 && !id_1 && !id_2); - if (id_0) { lookup = id_0->data; len = id_0->len; } else if (id_1) { lookup = id_1->data; len = id_1->len; - } else { + } else if (id_2) { lookup = id_2->data; len = id_2->len; + } else { + WARN_ON(1); + return ERR_PTR(-EINVAL); } /* Construct an identifier "id:<keyid>". */
In find_asymmetric_key(), if all NULLs are passed in the id_{0,1,2} arguments, the kernel will first emit WARN but then have an oops because id_2 gets dereferenced anyway. Add the missing id_2 check and move WARN_ON() to the final else branch to avoid duplicate NULL checks. Found by Linux Verification Center (linuxtesting.org) with Svace static analysis tool. Fixes: 7d30198ee24f ("keys: X.509 public key issuer lookup without AKID") Suggested-by: Sergey Shtylyov <s.shtylyov@omp.ru> Signed-off-by: Roman Smirnov <r.smirnov@omp.ru> Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru> --- V1 -> V2: updated patch description, returned WARN_ON() macro V2 -> V3: updated patch description crypto/asymmetric_keys/asymmetric_type.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)