| Message ID | 1fbaf516da763b50edac47d792a9145aa4482e29.1618442265.git.gustavoars@kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | Fix out-of-bounds warnings | expand |
On Wed, Apr 14, 2021 at 06:45:15PM -0500, Gustavo A. R. Silva wrote: > Fix the following out-of-bounds warnings by adding a new structure > wl3501_req instead of duplicating the same members in structure > wl3501_join_req and wl3501_scan_confirm: > > arch/x86/include/asm/string_32.h:182:25: warning: '__builtin_memcpy' offset [39, 108] from the object at 'sig' is out of the bounds of referenced subobject 'beacon_period' with type 'short unsigned int' at offset 36 [-Warray-bounds] > arch/x86/include/asm/string_32.h:182:25: warning: '__builtin_memcpy' offset [25, 95] from the object at 'sig' is out of the bounds of referenced subobject 'beacon_period' with type 'short unsigned int' at offset 22 [-Warray-bounds] > > Refactor the code, accordingly: > > $ pahole -C wl3501_req drivers/net/wireless/wl3501_cs.o > struct wl3501_req { > u16 beacon_period; /* 0 2 */ > u16 dtim_period; /* 2 2 */ > u16 cap_info; /* 4 2 */ > u8 bss_type; /* 6 1 */ > u8 bssid[6]; /* 7 6 */ > struct iw_mgmt_essid_pset ssid; /* 13 34 */ > struct iw_mgmt_ds_pset ds_pset; /* 47 3 */ > struct iw_mgmt_cf_pset cf_pset; /* 50 8 */ > struct iw_mgmt_ibss_pset ibss_pset; /* 58 4 */ > struct iw_mgmt_data_rset bss_basic_rset; /* 62 10 */ > > /* size: 72, cachelines: 2, members: 10 */ > /* last cacheline: 8 bytes */ > }; > > $ pahole -C wl3501_join_req drivers/net/wireless/wl3501_cs.o > struct wl3501_join_req { > u16 next_blk; /* 0 2 */ > u8 sig_id; /* 2 1 */ > u8 reserved; /* 3 1 */ > struct iw_mgmt_data_rset operational_rset; /* 4 10 */ > u16 reserved2; /* 14 2 */ > u16 timeout; /* 16 2 */ > u16 probe_delay; /* 18 2 */ > u8 timestamp[8]; /* 20 8 */ > u8 local_time[8]; /* 28 8 */ > struct wl3501_req req; /* 36 72 */ > > /* size: 108, cachelines: 2, members: 10 */ > /* last cacheline: 44 bytes */ > }; > > $ pahole -C wl3501_scan_confirm drivers/net/wireless/wl3501_cs.o > struct wl3501_scan_confirm { > u16 next_blk; /* 0 2 */ > u8 sig_id; /* 2 1 */ > u8 reserved; /* 3 1 */ > u16 status; /* 4 2 */ > char timestamp[8]; /* 6 8 */ > char localtime[8]; /* 14 8 */ > struct wl3501_req req; /* 22 72 */ > /* --- cacheline 1 boundary (64 bytes) was 30 bytes ago --- */ > u8 rssi; /* 94 1 */ > > /* size: 96, cachelines: 2, members: 8 */ > /* padding: 1 */ > /* last cacheline: 32 bytes */ > }; > > The problem is that the original code is trying to copy data into a > bunch of struct members adjacent to each other in a single call to > memcpy(). Now that a new struct wl3501_req enclosing all those adjacent > members is introduced, memcpy() doesn't overrun the length of > &sig.beacon_period and &this->bss_set[i].beacon_period, because the > address of the new struct object _req_ is used as the destination, > 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> > Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Awesome! Thank you for this solution. Reviewed-by: Kees Cook <keescook@chromium.org> -- Kees Cook
On 4/15/21 14:58, Kees Cook wrote: > On Wed, Apr 14, 2021 at 06:45:15PM -0500, Gustavo A. R. Silva wrote: >> Fix the following out-of-bounds warnings by adding a new structure >> wl3501_req instead of duplicating the same members in structure >> wl3501_join_req and wl3501_scan_confirm: >> >> arch/x86/include/asm/string_32.h:182:25: warning: '__builtin_memcpy' offset [39, 108] from the object at 'sig' is out of the bounds of referenced subobject 'beacon_period' with type 'short unsigned int' at offset 36 [-Warray-bounds] >> arch/x86/include/asm/string_32.h:182:25: warning: '__builtin_memcpy' offset [25, 95] from the object at 'sig' is out of the bounds of referenced subobject 'beacon_period' with type 'short unsigned int' at offset 22 [-Warray-bounds] >> >> Refactor the code, accordingly: >> >> $ pahole -C wl3501_req drivers/net/wireless/wl3501_cs.o >> struct wl3501_req { >> u16 beacon_period; /* 0 2 */ >> u16 dtim_period; /* 2 2 */ >> u16 cap_info; /* 4 2 */ >> u8 bss_type; /* 6 1 */ >> u8 bssid[6]; /* 7 6 */ >> struct iw_mgmt_essid_pset ssid; /* 13 34 */ >> struct iw_mgmt_ds_pset ds_pset; /* 47 3 */ >> struct iw_mgmt_cf_pset cf_pset; /* 50 8 */ >> struct iw_mgmt_ibss_pset ibss_pset; /* 58 4 */ >> struct iw_mgmt_data_rset bss_basic_rset; /* 62 10 */ >> >> /* size: 72, cachelines: 2, members: 10 */ >> /* last cacheline: 8 bytes */ >> }; >> >> $ pahole -C wl3501_join_req drivers/net/wireless/wl3501_cs.o >> struct wl3501_join_req { >> u16 next_blk; /* 0 2 */ >> u8 sig_id; /* 2 1 */ >> u8 reserved; /* 3 1 */ >> struct iw_mgmt_data_rset operational_rset; /* 4 10 */ >> u16 reserved2; /* 14 2 */ >> u16 timeout; /* 16 2 */ >> u16 probe_delay; /* 18 2 */ >> u8 timestamp[8]; /* 20 8 */ >> u8 local_time[8]; /* 28 8 */ >> struct wl3501_req req; /* 36 72 */ >> >> /* size: 108, cachelines: 2, members: 10 */ >> /* last cacheline: 44 bytes */ >> }; >> >> $ pahole -C wl3501_scan_confirm drivers/net/wireless/wl3501_cs.o >> struct wl3501_scan_confirm { >> u16 next_blk; /* 0 2 */ >> u8 sig_id; /* 2 1 */ >> u8 reserved; /* 3 1 */ >> u16 status; /* 4 2 */ >> char timestamp[8]; /* 6 8 */ >> char localtime[8]; /* 14 8 */ >> struct wl3501_req req; /* 22 72 */ >> /* --- cacheline 1 boundary (64 bytes) was 30 bytes ago --- */ >> u8 rssi; /* 94 1 */ >> >> /* size: 96, cachelines: 2, members: 8 */ >> /* padding: 1 */ >> /* last cacheline: 32 bytes */ >> }; >> >> The problem is that the original code is trying to copy data into a >> bunch of struct members adjacent to each other in a single call to >> memcpy(). Now that a new struct wl3501_req enclosing all those adjacent >> members is introduced, memcpy() doesn't overrun the length of >> &sig.beacon_period and &this->bss_set[i].beacon_period, because the >> address of the new struct object _req_ is used as the destination, >> 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> >> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> > > Awesome! Thank you for this solution. > > Reviewed-by: Kees Cook <keescook@chromium.org> Thanks, Kees! -- Gustavo
diff --git a/drivers/net/wireless/wl3501.h b/drivers/net/wireless/wl3501.h index aa8222cbea68..59b7b93c5963 100644 --- a/drivers/net/wireless/wl3501.h +++ b/drivers/net/wireless/wl3501.h @@ -379,16 +379,7 @@ struct wl3501_get_confirm { u8 mib_value[100]; }; -struct wl3501_join_req { - u16 next_blk; - u8 sig_id; - u8 reserved; - struct iw_mgmt_data_rset operational_rset; - u16 reserved2; - u16 timeout; - u16 probe_delay; - u8 timestamp[8]; - u8 local_time[8]; +struct wl3501_req { u16 beacon_period; u16 dtim_period; u16 cap_info; @@ -401,6 +392,19 @@ struct wl3501_join_req { struct iw_mgmt_data_rset bss_basic_rset; }; +struct wl3501_join_req { + u16 next_blk; + u8 sig_id; + u8 reserved; + struct iw_mgmt_data_rset operational_rset; + u16 reserved2; + u16 timeout; + u16 probe_delay; + u8 timestamp[8]; + u8 local_time[8]; + struct wl3501_req req; +}; + struct wl3501_join_confirm { u16 next_blk; u8 sig_id; @@ -443,16 +447,7 @@ struct wl3501_scan_confirm { u16 status; char timestamp[8]; char localtime[8]; - u16 beacon_period; - u16 dtim_period; - u16 cap_info; - u8 bss_type; - u8 bssid[ETH_ALEN]; - struct iw_mgmt_essid_pset ssid; - struct iw_mgmt_ds_pset ds_pset; - struct iw_mgmt_cf_pset cf_pset; - struct iw_mgmt_ibss_pset ibss_pset; - struct iw_mgmt_data_rset bss_basic_rset; + struct wl3501_req req; u8 rssi; }; diff --git a/drivers/net/wireless/wl3501_cs.c b/drivers/net/wireless/wl3501_cs.c index 70307308635f..672f5d5f3f2c 100644 --- a/drivers/net/wireless/wl3501_cs.c +++ b/drivers/net/wireless/wl3501_cs.c @@ -590,7 +590,7 @@ static int wl3501_mgmt_join(struct wl3501_card *this, u16 stas) struct wl3501_join_req sig = { .sig_id = WL3501_SIG_JOIN_REQ, .timeout = 10, - .ds_pset = { + .req.ds_pset = { .el = { .id = IW_MGMT_INFO_ELEMENT_DS_PARAMETER_SET, .len = 1, @@ -599,7 +599,7 @@ static int wl3501_mgmt_join(struct wl3501_card *this, u16 stas) }, }; - memcpy(&sig.beacon_period, &this->bss_set[stas].beacon_period, 72); + memcpy(&sig.req, &this->bss_set[stas].req, sizeof(sig.req)); return wl3501_esbq_exec(this, &sig, sizeof(sig)); } @@ -667,35 +667,37 @@ static void wl3501_mgmt_scan_confirm(struct wl3501_card *this, u16 addr) if (sig.status == WL3501_STATUS_SUCCESS) { pr_debug("success"); if ((this->net_type == IW_MODE_INFRA && - (sig.cap_info & WL3501_MGMT_CAPABILITY_ESS)) || + (sig.req.cap_info & WL3501_MGMT_CAPABILITY_ESS)) || (this->net_type == IW_MODE_ADHOC && - (sig.cap_info & WL3501_MGMT_CAPABILITY_IBSS)) || + (sig.req.cap_info & WL3501_MGMT_CAPABILITY_IBSS)) || this->net_type == IW_MODE_AUTO) { if (!this->essid.el.len) matchflag = 1; else if (this->essid.el.len == 3 && !memcmp(this->essid.essid, "ANY", 3)) matchflag = 1; - else if (this->essid.el.len != sig.ssid.el.len) + else if (this->essid.el.len != sig.req.ssid.el.len) matchflag = 0; - else if (memcmp(this->essid.essid, sig.ssid.essid, + else if (memcmp(this->essid.essid, sig.req.ssid.essid, this->essid.el.len)) matchflag = 0; else matchflag = 1; if (matchflag) { for (i = 0; i < this->bss_cnt; i++) { - if (ether_addr_equal_unaligned(this->bss_set[i].bssid, sig.bssid)) { + if (ether_addr_equal_unaligned(this->bss_set[i].req.bssid, + sig.req.bssid)) { matchflag = 0; break; } } } if (matchflag && (i < 20)) { - memcpy(&this->bss_set[i].beacon_period, - &sig.beacon_period, 73); + memcpy(&this->bss_set[i].req, + &sig.req, sizeof(sig.req)); this->bss_cnt++; this->rssi = sig.rssi; + this->bss_set[i].rssi = sig.rssi; } } } else if (sig.status == WL3501_STATUS_TIMEOUT) { @@ -887,19 +889,19 @@ static void wl3501_mgmt_join_confirm(struct net_device *dev, u16 addr) if (this->join_sta_bss < this->bss_cnt) { const int i = this->join_sta_bss; memcpy(this->bssid, - this->bss_set[i].bssid, ETH_ALEN); - this->chan = this->bss_set[i].ds_pset.chan; + this->bss_set[i].req.bssid, ETH_ALEN); + this->chan = this->bss_set[i].req.ds_pset.chan; iw_copy_mgmt_info_element(&this->keep_essid.el, - &this->bss_set[i].ssid.el); + &this->bss_set[i].req.ssid.el); wl3501_mgmt_auth(this); } } else { const int i = this->join_sta_bss; - memcpy(&this->bssid, &this->bss_set[i].bssid, ETH_ALEN); - this->chan = this->bss_set[i].ds_pset.chan; + memcpy(&this->bssid, &this->bss_set[i].req.bssid, ETH_ALEN); + this->chan = this->bss_set[i].req.ds_pset.chan; iw_copy_mgmt_info_element(&this->keep_essid.el, - &this->bss_set[i].ssid.el); + &this->bss_set[i].req.ssid.el); wl3501_online(dev); } } else { @@ -1573,30 +1575,30 @@ static int wl3501_get_scan(struct net_device *dev, struct iw_request_info *info, for (i = 0; i < this->bss_cnt; ++i) { iwe.cmd = SIOCGIWAP; iwe.u.ap_addr.sa_family = ARPHRD_ETHER; - memcpy(iwe.u.ap_addr.sa_data, this->bss_set[i].bssid, ETH_ALEN); + memcpy(iwe.u.ap_addr.sa_data, this->bss_set[i].req.bssid, ETH_ALEN); current_ev = iwe_stream_add_event(info, current_ev, extra + IW_SCAN_MAX_DATA, &iwe, IW_EV_ADDR_LEN); iwe.cmd = SIOCGIWESSID; iwe.u.data.flags = 1; - iwe.u.data.length = this->bss_set[i].ssid.el.len; + iwe.u.data.length = this->bss_set[i].req.ssid.el.len; current_ev = iwe_stream_add_point(info, current_ev, extra + IW_SCAN_MAX_DATA, &iwe, - this->bss_set[i].ssid.essid); + this->bss_set[i].req.ssid.essid); iwe.cmd = SIOCGIWMODE; - iwe.u.mode = this->bss_set[i].bss_type; + iwe.u.mode = this->bss_set[i].req.bss_type; current_ev = iwe_stream_add_event(info, current_ev, extra + IW_SCAN_MAX_DATA, &iwe, IW_EV_UINT_LEN); iwe.cmd = SIOCGIWFREQ; - iwe.u.freq.m = this->bss_set[i].ds_pset.chan; + iwe.u.freq.m = this->bss_set[i].req.ds_pset.chan; iwe.u.freq.e = 0; current_ev = iwe_stream_add_event(info, current_ev, extra + IW_SCAN_MAX_DATA, &iwe, IW_EV_FREQ_LEN); iwe.cmd = SIOCGIWENCODE; - if (this->bss_set[i].cap_info & WL3501_MGMT_CAPABILITY_PRIVACY) + if (this->bss_set[i].req.cap_info & WL3501_MGMT_CAPABILITY_PRIVACY) iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY; else iwe.u.data.flags = IW_ENCODE_DISABLED;
Fix the following out-of-bounds warnings by adding a new structure wl3501_req instead of duplicating the same members in structure wl3501_join_req and wl3501_scan_confirm: arch/x86/include/asm/string_32.h:182:25: warning: '__builtin_memcpy' offset [39, 108] from the object at 'sig' is out of the bounds of referenced subobject 'beacon_period' with type 'short unsigned int' at offset 36 [-Warray-bounds] arch/x86/include/asm/string_32.h:182:25: warning: '__builtin_memcpy' offset [25, 95] from the object at 'sig' is out of the bounds of referenced subobject 'beacon_period' with type 'short unsigned int' at offset 22 [-Warray-bounds] Refactor the code, accordingly: $ pahole -C wl3501_req drivers/net/wireless/wl3501_cs.o struct wl3501_req { u16 beacon_period; /* 0 2 */ u16 dtim_period; /* 2 2 */ u16 cap_info; /* 4 2 */ u8 bss_type; /* 6 1 */ u8 bssid[6]; /* 7 6 */ struct iw_mgmt_essid_pset ssid; /* 13 34 */ struct iw_mgmt_ds_pset ds_pset; /* 47 3 */ struct iw_mgmt_cf_pset cf_pset; /* 50 8 */ struct iw_mgmt_ibss_pset ibss_pset; /* 58 4 */ struct iw_mgmt_data_rset bss_basic_rset; /* 62 10 */ /* size: 72, cachelines: 2, members: 10 */ /* last cacheline: 8 bytes */ }; $ pahole -C wl3501_join_req drivers/net/wireless/wl3501_cs.o struct wl3501_join_req { u16 next_blk; /* 0 2 */ u8 sig_id; /* 2 1 */ u8 reserved; /* 3 1 */ struct iw_mgmt_data_rset operational_rset; /* 4 10 */ u16 reserved2; /* 14 2 */ u16 timeout; /* 16 2 */ u16 probe_delay; /* 18 2 */ u8 timestamp[8]; /* 20 8 */ u8 local_time[8]; /* 28 8 */ struct wl3501_req req; /* 36 72 */ /* size: 108, cachelines: 2, members: 10 */ /* last cacheline: 44 bytes */ }; $ pahole -C wl3501_scan_confirm drivers/net/wireless/wl3501_cs.o struct wl3501_scan_confirm { u16 next_blk; /* 0 2 */ u8 sig_id; /* 2 1 */ u8 reserved; /* 3 1 */ u16 status; /* 4 2 */ char timestamp[8]; /* 6 8 */ char localtime[8]; /* 14 8 */ struct wl3501_req req; /* 22 72 */ /* --- cacheline 1 boundary (64 bytes) was 30 bytes ago --- */ u8 rssi; /* 94 1 */ /* size: 96, cachelines: 2, members: 8 */ /* padding: 1 */ /* last cacheline: 32 bytes */ }; The problem is that the original code is trying to copy data into a bunch of struct members adjacent to each other in a single call to memcpy(). Now that a new struct wl3501_req enclosing all those adjacent members is introduced, memcpy() doesn't overrun the length of &sig.beacon_period and &this->bss_set[i].beacon_period, because the address of the new struct object _req_ is used as the destination, 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> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> --- Changes in v3: - Add new struct wl3501_req and refactor the code, accordingly. - Fix one more instance of this same issue. - Update changelog text. Changes in v2: - None. drivers/net/wireless/wl3501.h | 35 +++++++++++-------------- drivers/net/wireless/wl3501_cs.c | 44 +++++++++++++++++--------------- 2 files changed, 38 insertions(+), 41 deletions(-)