| Message ID | 20241006221221.3744995-1-artem.chernyshev@red-soft.ru (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net] pktgen: Avoid out-of-range in get_imix_entries | expand |
On Mon, 7 Oct 2024 01:12:20 +0300 Artem Chernyshev wrote: > In get_imit_enries() pkt_dev->n_imix_entries = MAX_IMIX_ENTRIES > leads to oob for pkt_dev->imix_entries array. I don't think so, at least not exactly. It's legal to fill the array completely. It's not legal to try to _add_ to an already full array. AFAICT the fix needs more work.
Thank you for the review. I will return with V2 Best regards, Artem On Tue, Oct 08, 2024 at 06:23:19PM -0700, Jakub Kicinski wrote: > On Mon, 7 Oct 2024 01:12:20 +0300 Artem Chernyshev wrote: > > In get_imit_enries() pkt_dev->n_imix_entries = MAX_IMIX_ENTRIES > > leads to oob for pkt_dev->imix_entries array. > > I don't think so, at least not exactly. It's legal to fill the array > completely. It's not legal to try to _add_ to an already full array. > > AFAICT the fix needs more work. > -- > pw-bot: cr
diff --git a/net/core/pktgen.c b/net/core/pktgen.c index 34f68ef74b8f..97cf5c797a22 100644 --- a/net/core/pktgen.c +++ b/net/core/pktgen.c @@ -881,7 +881,7 @@ static ssize_t get_imix_entries(const char __user *buffer, i++; pkt_dev->n_imix_entries++; - if (pkt_dev->n_imix_entries > MAX_IMIX_ENTRIES) + if (pkt_dev->n_imix_entries >= MAX_IMIX_ENTRIES) return -E2BIG; } while (c == ' ');
In get_imit_enries() pkt_dev->n_imix_entries = MAX_IMIX_ENTRIES leads to oob for pkt_dev->imix_entries array. ``` UBSAN: array-index-out-of-bounds in net/core/pktgen.c:874:24 index 20 is out of range for type 'imix_pkt [20]' CPU: 2 PID: 1210 Comm: bash Not tainted 6.10.0-rc1 #121 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) Call Trace: <TASK> dump_stack_lvl lib/dump_stack.c:117 __ubsan_handle_out_of_bounds lib/ubsan.c:429 get_imix_entries net/core/pktgen.c:874 pktgen_if_write net/core/pktgen.c:1063 pde_write fs/proc/inode.c:334 proc_reg_write fs/proc/inode.c:346 vfs_write fs/read_write.c:593 ksys_write fs/read_write.c:644 do_syscall_64 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe arch/x86/entry/entry_64.S:130 RIP: 0033:0x7f148408b240 ``` Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 52a62f8603f9 ("pktgen: Parse internet mix (imix) input") Signed-off-by: Artem Chernyshev <artem.chernyshev@red-soft.ru> --- net/core/pktgen.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)