| Message ID | d260fe56aed7112bff2be5b4d152d03ad7b78e78.1618442265.git.gustavoars@kernel.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 820aa37638a252b57967bdf4038a514b1ab85d45 |
| Delegated to: | Kalle Valo |
| Headers | show |
| Series | Fix out-of-bounds warnings | expand |
"Gustavo A. R. Silva" <gustavoars@kernel.org> wrote: > Fix the following out-of-bounds warnings by enclosing structure members > daddr and saddr into new struct addr, in structures wl3501_md_req and > wl3501_md_ind: > > arch/x86/include/asm/string_32.h:182:25: warning: '__builtin_memcpy' offset [18, 23] from the object at 'sig' is out of the bounds of referenced subobject 'daddr' with type 'u8[6]' {aka 'unsigned char[6]'} at offset 11 [-Warray-bounds] > arch/x86/include/asm/string_32.h:182:25: warning: '__builtin_memcpy' offset [18, 23] from the object at 'sig' is out of the bounds of referenced subobject 'daddr' with type 'u8[6]' {aka 'unsigned char[6]'} at offset 11 [-Warray-bounds] > > Refactor the code, accordingly: > > $ pahole -C wl3501_md_req drivers/net/wireless/wl3501_cs.o > struct wl3501_md_req { > u16 next_blk; /* 0 2 */ > u8 sig_id; /* 2 1 */ > u8 routing; /* 3 1 */ > u16 data; /* 4 2 */ > u16 size; /* 6 2 */ > u8 pri; /* 8 1 */ > u8 service_class; /* 9 1 */ > struct { > u8 daddr[6]; /* 10 6 */ > u8 saddr[6]; /* 16 6 */ > } addr; /* 10 12 */ > > /* size: 22, cachelines: 1, members: 8 */ > /* last cacheline: 22 bytes */ > }; > > $ pahole -C wl3501_md_ind drivers/net/wireless/wl3501_cs.o > struct wl3501_md_ind { > u16 next_blk; /* 0 2 */ > u8 sig_id; /* 2 1 */ > u8 routing; /* 3 1 */ > u16 data; /* 4 2 */ > u16 size; /* 6 2 */ > u8 reception; /* 8 1 */ > u8 pri; /* 9 1 */ > u8 service_class; /* 10 1 */ > struct { > u8 daddr[6]; /* 11 6 */ > u8 saddr[6]; /* 17 6 */ > } addr; /* 11 12 */ > > /* size: 24, cachelines: 1, members: 9 */ > /* padding: 1 */ > /* last cacheline: 24 bytes */ > }; > > The problem is that the original code is trying to copy data into a > couple of arrays adjacent to each other in a single call to memcpy(). > Now that a new struct _addr_ enclosing those two adjacent arrays > is introduced, memcpy() doesn't overrun the length of &sig.daddr[0] > and &sig.daddr, because the address of the new struct object _addr_ > is used, instead. > > This helps with the ongoing efforts to globally enable -Warray-bounds > and get us closer to being able to tighten the FORTIFY_SOURCE routines > on memcpy(). > > Link: https://github.com/KSPP/linux/issues/109 > Reported-by: kernel test robot <lkp@intel.com> > Reviewed-by: Kees Cook <keescook@chromium.org> > Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> 2 patches applied to wireless-drivers-next.git, thanks. 820aa37638a2 wl3501_cs: Fix out-of-bounds warnings in wl3501_send_pkt bb43e5718d8f wl3501_cs: Fix out-of-bounds warnings in wl3501_mgmt_join
On 4/22/21 09:39, Kalle Valo wrote: > 2 patches applied to wireless-drivers-next.git, thanks. > > 820aa37638a2 wl3501_cs: Fix out-of-bounds warnings in wl3501_send_pkt > bb43e5718d8f wl3501_cs: Fix out-of-bounds warnings in wl3501_mgmt_join Thanks, Kalle. -- Gustavo
diff --git a/drivers/net/wireless/wl3501.h b/drivers/net/wireless/wl3501.h index e98e04ee9a2c..aa8222cbea68 100644 --- a/drivers/net/wireless/wl3501.h +++ b/drivers/net/wireless/wl3501.h @@ -471,8 +471,10 @@ struct wl3501_md_req { u16 size; u8 pri; u8 service_class; - u8 daddr[ETH_ALEN]; - u8 saddr[ETH_ALEN]; + struct { + u8 daddr[ETH_ALEN]; + u8 saddr[ETH_ALEN]; + } addr; }; struct wl3501_md_ind { @@ -484,8 +486,10 @@ struct wl3501_md_ind { u8 reception; u8 pri; u8 service_class; - u8 daddr[ETH_ALEN]; - u8 saddr[ETH_ALEN]; + struct { + u8 daddr[ETH_ALEN]; + u8 saddr[ETH_ALEN]; + } addr; }; struct wl3501_md_confirm { diff --git a/drivers/net/wireless/wl3501_cs.c b/drivers/net/wireless/wl3501_cs.c index 8ca5789c7b37..70307308635f 100644 --- a/drivers/net/wireless/wl3501_cs.c +++ b/drivers/net/wireless/wl3501_cs.c @@ -469,6 +469,7 @@ static int wl3501_send_pkt(struct wl3501_card *this, u8 *data, u16 len) struct wl3501_md_req sig = { .sig_id = WL3501_SIG_MD_REQ, }; + size_t sig_addr_len = sizeof(sig.addr); u8 *pdata = (char *)data; int rc = -EIO; @@ -484,9 +485,9 @@ static int wl3501_send_pkt(struct wl3501_card *this, u8 *data, u16 len) goto out; } rc = 0; - memcpy(&sig.daddr[0], pdata, 12); - pktlen = len - 12; - pdata += 12; + memcpy(&sig.addr, pdata, sig_addr_len); + pktlen = len - sig_addr_len; + pdata += sig_addr_len; sig.data = bf; if (((*pdata) * 256 + (*(pdata + 1))) > 1500) { u8 addr4[ETH_ALEN] = { @@ -980,7 +981,8 @@ static inline void wl3501_md_ind_interrupt(struct net_device *dev, } else { skb->dev = dev; skb_reserve(skb, 2); /* IP headers on 16 bytes boundaries */ - skb_copy_to_linear_data(skb, (unsigned char *)&sig.daddr, 12); + skb_copy_to_linear_data(skb, (unsigned char *)&sig.addr, + sizeof(sig.addr)); wl3501_receive(this, skb->data, pkt_len); skb_put(skb, pkt_len); skb->protocol = eth_type_trans(skb, dev);
Fix the following out-of-bounds warnings by enclosing structure members daddr and saddr into new struct addr, in structures wl3501_md_req and wl3501_md_ind: arch/x86/include/asm/string_32.h:182:25: warning: '__builtin_memcpy' offset [18, 23] from the object at 'sig' is out of the bounds of referenced subobject 'daddr' with type 'u8[6]' {aka 'unsigned char[6]'} at offset 11 [-Warray-bounds] arch/x86/include/asm/string_32.h:182:25: warning: '__builtin_memcpy' offset [18, 23] from the object at 'sig' is out of the bounds of referenced subobject 'daddr' with type 'u8[6]' {aka 'unsigned char[6]'} at offset 11 [-Warray-bounds] Refactor the code, accordingly: $ pahole -C wl3501_md_req drivers/net/wireless/wl3501_cs.o struct wl3501_md_req { u16 next_blk; /* 0 2 */ u8 sig_id; /* 2 1 */ u8 routing; /* 3 1 */ u16 data; /* 4 2 */ u16 size; /* 6 2 */ u8 pri; /* 8 1 */ u8 service_class; /* 9 1 */ struct { u8 daddr[6]; /* 10 6 */ u8 saddr[6]; /* 16 6 */ } addr; /* 10 12 */ /* size: 22, cachelines: 1, members: 8 */ /* last cacheline: 22 bytes */ }; $ pahole -C wl3501_md_ind drivers/net/wireless/wl3501_cs.o struct wl3501_md_ind { u16 next_blk; /* 0 2 */ u8 sig_id; /* 2 1 */ u8 routing; /* 3 1 */ u16 data; /* 4 2 */ u16 size; /* 6 2 */ u8 reception; /* 8 1 */ u8 pri; /* 9 1 */ u8 service_class; /* 10 1 */ struct { u8 daddr[6]; /* 11 6 */ u8 saddr[6]; /* 17 6 */ } addr; /* 11 12 */ /* size: 24, cachelines: 1, members: 9 */ /* padding: 1 */ /* last cacheline: 24 bytes */ }; The problem is that the original code is trying to copy data into a couple of arrays adjacent to each other in a single call to memcpy(). Now that a new struct _addr_ enclosing those two adjacent arrays is introduced, memcpy() doesn't overrun the length of &sig.daddr[0] and &sig.daddr, because the address of the new struct object _addr_ is used, instead. This helps with the ongoing efforts to globally enable -Warray-bounds and get us closer to being able to tighten the FORTIFY_SOURCE routines on memcpy(). Link: https://github.com/KSPP/linux/issues/109 Reported-by: kernel test robot <lkp@intel.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> --- Changes in v3: - Enclose adjacent members in struct wl3501_md_ind into new struct req. - Fix one more instance of this same issue in function wl3501_md_ind_interrupt(). - Update changelog text. - Add Kees' RB tag. Changes in v2: - Update changelog text. - Replace a couple of magic numbers with new variable sig_addr_len. drivers/net/wireless/wl3501.h | 12 ++++++++---- drivers/net/wireless/wl3501_cs.c | 10 ++++++---- 2 files changed, 14 insertions(+), 8 deletions(-)