B.A.T.M.A.N May 2024

b.a.t.m.a.n@lists.open-mesh.org

5 participants
5 discussions

About Throughput in BATMAN_V
by berkay.demirci＠protonmail.com 19 May '24

19 May '24

Hello, I have a question about Batman V's behavior about throughput. Batman doesn't seem to calculate throughput properly so we set it manually with throughput override, but then even when actual throughput of the active interface decreases, it doesn't switch to the other interface because it only considers the overriden value. It only switches when the active interface stops receiving OGM's completely. I think if throughput was calculated properly this wouldn't be a problem so i want to ask why it's the way it is. Batman already has a tool called throughout meter, shouldn't it be used to continuously check the value?

3 9

[PATCH] wifi: cfg80211: Lock wiphy in cfg80211_get_station
by Remi Pommarel 18 May '24

18 May '24

Wiphy should be locked before calling rdev_get_station() (see lockdep assert in ieee80211_get_station()). This fixes the following kernel NULL dereference: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000050 Mem abort info: ESR = 0x0000000096000006 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x06: level 2 translation fault Data abort info: ISV = 0, ISS = 0x00000006 CM = 0, WnR = 0 user pgtable: 4k pages, 48-bit VAs, pgdp=0000000003001000 [0000000000000050] pgd=0800000002dca003, p4d=0800000002dca003, pud=08000000028e9003, pmd=0000000000000000 Internal error: Oops: 0000000096000006 [#1] SMP Modules linked in: netconsole dwc3_meson_g12a dwc3_of_simple dwc3 ip_gre gre ath10k_pci ath10k_core ath9k ath9k_common ath9k_hw ath CPU: 0 PID: 1091 Comm: kworker/u8:0 Not tainted 6.4.0-02144-g565f9a3a7911-dirty #705 Hardware name: RPT (r1) (DT) Workqueue: bat_events batadv_v_elp_throughput_metric_update pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : ath10k_sta_statistics+0x10/0x2dc [ath10k_core] lr : sta_set_sinfo+0xcc/0xbd4 sp : ffff000007b43ad0 x29: ffff000007b43ad0 x28: ffff0000071fa900 x27: ffff00000294ca98 x26: ffff000006830880 x25: ffff000006830880 x24: ffff00000294c000 x23: 0000000000000001 x22: ffff000007b43c90 x21: ffff800008898acc x20: ffff00000294c6e8 x19: ffff000007b43c90 x18: 0000000000000000 x17: 445946354d552d78 x16: 62661f7200000000 x15: 57464f445946354d x14: 0000000000000000 x13: 00000000000000e3 x12: d5f0acbcebea978e x11: 00000000000000e3 x10: 000000010048fe41 x9 : 0000000000000000 x8 : ffff000007b43d90 x7 : 000000007a1e2125 x6 : 0000000000000000 x5 : ffff0000024e0900 x4 : ffff800000a0250c x3 : ffff000007b43c90 x2 : ffff00000294ca98 x1 : ffff000006831920 x0 : 0000000000000000 Call trace: ath10k_sta_statistics+0x10/0x2dc [ath10k_core] sta_set_sinfo+0xcc/0xbd4 ieee80211_get_station+0x2c/0x44 cfg80211_get_station+0x80/0x154 batadv_v_elp_get_throughput+0x138/0x1fc batadv_v_elp_throughput_metric_update+0x1c/0xa4 process_one_work+0x1ec/0x414 worker_thread+0x70/0x46c kthread+0xdc/0xe0 ret_from_fork+0x10/0x20 Code: a9bb7bfd 910003fd a90153f3 f9411c40 (f9402814) Fixes: 7406353d43c8 ("cfg80211: implement cfg80211_get_station cfg80211 API") Signed-off-by: Remi Pommarel <repk(a)triplefau.lt> --- net/wireless/util.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/net/wireless/util.c b/net/wireless/util.c index 2bde8a354631..082c6f9c5416 100644 --- a/net/wireless/util.c +++ b/net/wireless/util.c @@ -2549,6 +2549,7 @@ int cfg80211_get_station(struct net_device *dev, const u8 *mac_addr, { struct cfg80211_registered_device *rdev; struct wireless_dev *wdev; + int ret; wdev = dev->ieee80211_ptr; if (!wdev) @@ -2560,7 +2561,11 @@ int cfg80211_get_station(struct net_device *dev, const u8 *mac_addr, memset(sinfo, 0, sizeof(*sinfo)); - return rdev_get_station(rdev, dev, mac_addr, sinfo); + wiphy_lock(&rdev->wiphy); + ret = rdev_get_station(rdev, dev, mac_addr, sinfo); + wiphy_unlock(&rdev->wiphy); + + return ret; } EXPORT_SYMBOL(cfg80211_get_station); -- 2.40.0

1 0

[PATCH v3] batman-adv: Add flex array to struct batadv_tvlv_tt_data
by Erick Archer 09 May '24

09 May '24

The "struct batadv_tvlv_tt_data" uses a dynamically sized set of trailing elements. Specifically, it uses an array of structures of type "batadv_tvlv_tt_vlan_data". So, use the preferred way in the kernel declaring a flexible array [1]. At the same time, prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions). In this case, it is important to note that the attribute used is specifically __counted_by_be since variable "num_vlan" is of type __be16. The following change to the "batadv_tt_tvlv_ogm_handler_v1" function: - tt_vlan = (struct batadv_tvlv_tt_vlan_data *)(tt_data + 1); - tt_change = (struct batadv_tvlv_tt_change *)(tt_vlan + num_vlan); + tt_change = (struct batadv_tvlv_tt_change *)((void *)tt_data + + flex_size); is intended to prevent the compiler from generating an "out-of-bounds" notification due to the __counted_by attribute. The compiler can do a pointer calculation using the vlan_data flexible array memory, or in other words, this may be calculated as an array offset, since it is the same as: &tt_data->vlan_data[num_vlan] Therefore, we go past the end of the array. In other "multiple trailing flexible array" situations, this has been solved by addressing from the base pointer, since the compiler either knows the full allocation size or it knows nothing about it (this case, since it came from a "void *" function argument). The order in which the structure batadv_tvlv_tt_data and the structure batadv_tvlv_tt_vlan_data are defined must be swap to avoid an incomplete type error. Also, avoid the open-coded arithmetic in memory allocator functions [2] using the "struct_size" macro and use the "flex_array_size" helper to clarify some calculations, when possible. Moreover, the new structure member also allow us to avoid the open-coded arithmetic on pointers in some situations. Take advantage of this. This code was detected with the help of Coccinelle, and audited and modified manually. Link: https://www.kernel.org/doc/html/next/process/deprecated.html#zero-length-an… [1] Link: https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-ari… [2] Signed-off-by: Erick Archer <erick.archer(a)outlook.com> --- Changes in v2: - Add the #include of <linux/overflow.h> for the "flex_array_size" helper (Sven Eckelmann). - Add the "ntohs" function to the "flex_array_size" helper removed by mistake during the conversion (Sven Eckelmann). - Add the "__counted_by_be" attribute. Changes in v3: - Address from the base pointer tt_data to avoid an "out-of-bounds" notification (Kees Cook). - Update the commit message to explain the new change. Previous versions: v1 -> https://lore.kernel.org/linux-hardening/AS8PR02MB7237987BF9DFCA030B330F658B… v2 -> https://lore.kernel.org/linux-hardening/AS8PR02MB723756E3D1366C4E8FCD14BF8B… Hi, The Coccinelle script used to detect this code pattern is the following: virtual report @rule1@ type t1; type t2; identifier i0; identifier i1; identifier i2; identifier ALLOC =~ "kmalloc|kzalloc|kmalloc_node|kzalloc_node|vmalloc|vzalloc|kvmalloc|kvzalloc"; position p1; @@ i0 = sizeof(t1) + sizeof(t2) * i1; ... i2 = ALLOC@p1(..., i0, ...); @script:python depends on report@ p1 << rule1.p1; @@ msg = "WARNING: verify allocation on line %s" % (p1[0].line) coccilib.report.print_report(p1[0],msg) Regards, Erick --- include/uapi/linux/batadv_packet.h | 28 +++++++++-------- net/batman-adv/translation-table.c | 49 ++++++++++++------------------ 2 files changed, 35 insertions(+), 42 deletions(-) diff --git a/include/uapi/linux/batadv_packet.h b/include/uapi/linux/batadv_packet.h index 6e25753015df..dfbe30536995 100644 --- a/include/uapi/linux/batadv_packet.h +++ b/include/uapi/linux/batadv_packet.h @@ -592,19 +592,6 @@ struct batadv_tvlv_gateway_data { __be32 bandwidth_up; }; -/** - * struct batadv_tvlv_tt_data - tt data propagated through the tt tvlv container - * @flags: translation table flags (see batadv_tt_data_flags) - * @ttvn: translation table version number - * @num_vlan: number of announced VLANs. In the TVLV this struct is followed by - * one batadv_tvlv_tt_vlan_data object per announced vlan - */ -struct batadv_tvlv_tt_data { - __u8 flags; - __u8 ttvn; - __be16 num_vlan; -}; - /** * struct batadv_tvlv_tt_vlan_data - vlan specific tt data propagated through * the tt tvlv container @@ -618,6 +605,21 @@ struct batadv_tvlv_tt_vlan_data { __u16 reserved; }; +/** + * struct batadv_tvlv_tt_data - tt data propagated through the tt tvlv container + * @flags: translation table flags (see batadv_tt_data_flags) + * @ttvn: translation table version number + * @num_vlan: number of announced VLANs. In the TVLV this struct is followed by + * one batadv_tvlv_tt_vlan_data object per announced vlan + * @vlan_data: array of batadv_tvlv_tt_vlan_data objects + */ +struct batadv_tvlv_tt_data { + __u8 flags; + __u8 ttvn; + __be16 num_vlan; + struct batadv_tvlv_tt_vlan_data vlan_data[] __counted_by_be(num_vlan); +}; + /** * struct batadv_tvlv_tt_change - translation table diff data * @flags: status indicators concerning the non-mesh client (see diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c index b21ff3c36b07..b44c382226a1 100644 --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -28,6 +28,7 @@ #include <linux/net.h> #include <linux/netdevice.h> #include <linux/netlink.h> +#include <linux/overflow.h> #include <linux/rculist.h> #include <linux/rcupdate.h> #include <linux/skbuff.h> @@ -815,8 +816,7 @@ batadv_tt_prepare_tvlv_global_data(struct batadv_orig_node *orig_node, num_entries += atomic_read(&vlan->tt.num_entries); } - change_offset = sizeof(**tt_data); - change_offset += num_vlan * sizeof(*tt_vlan); + change_offset = struct_size(*tt_data, vlan_data, num_vlan); /* if tt_len is negative, allocate the space needed by the full table */ if (*tt_len < 0) @@ -835,7 +835,7 @@ batadv_tt_prepare_tvlv_global_data(struct batadv_orig_node *orig_node, (*tt_data)->ttvn = atomic_read(&orig_node->last_ttvn); (*tt_data)->num_vlan = htons(num_vlan); - tt_vlan = (struct batadv_tvlv_tt_vlan_data *)(*tt_data + 1); + tt_vlan = (*tt_data)->vlan_data; hlist_for_each_entry(vlan, &orig_node->vlan_list, list) { tt_vlan->vid = htons(vlan->vid); tt_vlan->crc = htonl(vlan->tt.crc); @@ -895,8 +895,7 @@ batadv_tt_prepare_tvlv_local_data(struct batadv_priv *bat_priv, total_entries += vlan_entries; } - change_offset = sizeof(**tt_data); - change_offset += num_vlan * sizeof(*tt_vlan); + change_offset = struct_size(*tt_data, vlan_data, num_vlan); /* if tt_len is negative, allocate the space needed by the full table */ if (*tt_len < 0) @@ -915,7 +914,7 @@ batadv_tt_prepare_tvlv_local_data(struct batadv_priv *bat_priv, (*tt_data)->ttvn = atomic_read(&bat_priv->tt.vn); (*tt_data)->num_vlan = htons(num_vlan); - tt_vlan = (struct batadv_tvlv_tt_vlan_data *)(*tt_data + 1); + tt_vlan = (*tt_data)->vlan_data; hlist_for_each_entry(vlan, &bat_priv->softif_vlan_list, list) { vlan_entries = atomic_read(&vlan->tt.num_entries); if (vlan_entries < 1) @@ -2875,7 +2874,6 @@ static bool batadv_send_tt_request(struct batadv_priv *bat_priv, { struct batadv_tvlv_tt_data *tvlv_tt_data = NULL; struct batadv_tt_req_node *tt_req_node = NULL; - struct batadv_tvlv_tt_vlan_data *tt_vlan_req; struct batadv_hard_iface *primary_if; bool ret = false; int i, size; @@ -2891,7 +2889,7 @@ static bool batadv_send_tt_request(struct batadv_priv *bat_priv, if (!tt_req_node) goto out; - size = sizeof(*tvlv_tt_data) + sizeof(*tt_vlan_req) * num_vlan; + size = struct_size(tvlv_tt_data, vlan_data, num_vlan); tvlv_tt_data = kzalloc(size, GFP_ATOMIC); if (!tvlv_tt_data) goto out; @@ -2903,12 +2901,10 @@ static bool batadv_send_tt_request(struct batadv_priv *bat_priv, /* send all the CRCs within the request. This is needed by intermediate * nodes to ensure they have the correct table before replying */ - tt_vlan_req = (struct batadv_tvlv_tt_vlan_data *)(tvlv_tt_data + 1); for (i = 0; i < num_vlan; i++) { - tt_vlan_req->vid = tt_vlan->vid; - tt_vlan_req->crc = tt_vlan->crc; + tvlv_tt_data->vlan_data[i].vid = tt_vlan->vid; + tvlv_tt_data->vlan_data[i].crc = tt_vlan->crc; - tt_vlan_req++; tt_vlan++; } @@ -2960,7 +2956,6 @@ static bool batadv_send_other_tt_response(struct batadv_priv *bat_priv, struct batadv_orig_node *res_dst_orig_node = NULL; struct batadv_tvlv_tt_change *tt_change; struct batadv_tvlv_tt_data *tvlv_tt_data = NULL; - struct batadv_tvlv_tt_vlan_data *tt_vlan; bool ret = false, full_table; u8 orig_ttvn, req_ttvn; u16 tvlv_len; @@ -2983,10 +2978,9 @@ static bool batadv_send_other_tt_response(struct batadv_priv *bat_priv, orig_ttvn = (u8)atomic_read(&req_dst_orig_node->last_ttvn); req_ttvn = tt_data->ttvn; - tt_vlan = (struct batadv_tvlv_tt_vlan_data *)(tt_data + 1); /* this node doesn't have the requested data */ if (orig_ttvn != req_ttvn || - !batadv_tt_global_check_crc(req_dst_orig_node, tt_vlan, + !batadv_tt_global_check_crc(req_dst_orig_node, tt_data->vlan_data, ntohs(tt_data->num_vlan))) goto out; @@ -3329,7 +3323,6 @@ static void batadv_handle_tt_response(struct batadv_priv *bat_priv, struct batadv_orig_node *orig_node = NULL; struct batadv_tvlv_tt_change *tt_change; u8 *tvlv_ptr = (u8 *)tt_data; - u16 change_offset; batadv_dbg(BATADV_DBG_TT, bat_priv, "Received TT_RESPONSE from %pM for ttvn %d t_size: %d [%c]\n", @@ -3342,10 +3335,7 @@ static void batadv_handle_tt_response(struct batadv_priv *bat_priv, spin_lock_bh(&orig_node->tt_lock); - change_offset = sizeof(struct batadv_tvlv_tt_vlan_data); - change_offset *= ntohs(tt_data->num_vlan); - change_offset += sizeof(*tt_data); - tvlv_ptr += change_offset; + tvlv_ptr += struct_size(tt_data, vlan_data, ntohs(tt_data->num_vlan)); tt_change = (struct batadv_tvlv_tt_change *)tvlv_ptr; if (tt_data->flags & BATADV_TT_FULL_TABLE) { @@ -3944,10 +3934,10 @@ static void batadv_tt_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv, u8 flags, void *tvlv_value, u16 tvlv_value_len) { - struct batadv_tvlv_tt_vlan_data *tt_vlan; struct batadv_tvlv_tt_change *tt_change; struct batadv_tvlv_tt_data *tt_data; u16 num_entries, num_vlan; + size_t flex_size; if (tvlv_value_len < sizeof(*tt_data)) return; @@ -3957,17 +3947,18 @@ static void batadv_tt_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv, num_vlan = ntohs(tt_data->num_vlan); - if (tvlv_value_len < sizeof(*tt_vlan) * num_vlan) + flex_size = flex_array_size(tt_data, vlan_data, num_vlan); + if (tvlv_value_len < flex_size) return; - tt_vlan = (struct batadv_tvlv_tt_vlan_data *)(tt_data + 1); - tt_change = (struct batadv_tvlv_tt_change *)(tt_vlan + num_vlan); - tvlv_value_len -= sizeof(*tt_vlan) * num_vlan; + tt_change = (struct batadv_tvlv_tt_change *)((void *)tt_data + + flex_size); + tvlv_value_len -= flex_size; num_entries = batadv_tt_entries(tvlv_value_len); - batadv_tt_update_orig(bat_priv, orig, tt_vlan, num_vlan, tt_change, - num_entries, tt_data->ttvn); + batadv_tt_update_orig(bat_priv, orig, tt_data->vlan_data, num_vlan, + tt_change, num_entries, tt_data->ttvn); } /** @@ -3998,8 +3989,8 @@ static int batadv_tt_tvlv_unicast_handler_v1(struct batadv_priv *bat_priv, tt_data = tvlv_value; tvlv_value_len -= sizeof(*tt_data); - tt_vlan_len = sizeof(struct batadv_tvlv_tt_vlan_data); - tt_vlan_len *= ntohs(tt_data->num_vlan); + tt_vlan_len = flex_array_size(tt_data, vlan_data, + ntohs(tt_data->num_vlan)); if (tvlv_value_len < tt_vlan_len) return NET_RX_SUCCESS; -- 2.25.1

3 7

[PATCH] batman-adv: Don't accept TT entries for out-of-spec VIDs
by Sven Eckelmann 04 May '24

04 May '24

The internal handling of VLAN IDs in batman-adv is only specified for following encodings: * VLAN is used - bit 15 is 1 - bit 11 - bit 0 is the VLAN ID (0-4095) - remaining bits are 0 * No VLAN is used - bit 15 is 0 - remaining bits are 0 batman-adv was only preparing new translation table entries (based on its soft interface information) using this encoding format. But the receive path was never checking if entries in the roam or TT TVLVs were also following this encoding. It was therefore possible to create more than the expected maximum of 4096 + 1 entries in the originator VLAN list. Simply by setting the "remaining bits" to "random" values in corresponding TVLV. Fixes: 21a57f6e7a3b ("batman-adv: make the TT CRC logic VLAN specific") Reported-by: Linus Lüssing <linus.luessing(a)c0d3.blue> Signed-off-by: Sven Eckelmann <sven(a)narfation.org> --- net/batman-adv/originator.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c index ac74f6ea..8f6dd2c6 100644 --- a/net/batman-adv/originator.c +++ b/net/batman-adv/originator.c @@ -12,6 +12,7 @@ #include <linux/errno.h> #include <linux/etherdevice.h> #include <linux/gfp.h> +#include <linux/if_vlan.h> #include <linux/jiffies.h> #include <linux/kref.h> #include <linux/list.h> @@ -131,6 +132,29 @@ batadv_orig_node_vlan_get(struct batadv_orig_node *orig_node, return vlan; } +/** + * batadv_vlan_id_valid() - check if vlan id is in valid batman-adv encoding + * @vid: the VLAN identifier + * + * Return: true when either no vlan is set or if VLAN is in correct range, + * false otherwise + */ +static bool batadv_vlan_id_valid(unsigned short vid) +{ + unsigned short non_vlan = vid & ~(BATADV_VLAN_HAS_TAG | VLAN_VID_MASK); + + if (vid == 0) + return true; + + if (!(vid & BATADV_VLAN_HAS_TAG)) + return false; + + if (non_vlan) + return false; + + return true; +} + /** * batadv_orig_node_vlan_new() - search and possibly create an orig_node_vlan * object @@ -149,6 +173,9 @@ batadv_orig_node_vlan_new(struct batadv_orig_node *orig_node, { struct batadv_orig_node_vlan *vlan; + if (!batadv_vlan_id_valid(vid)) + return NULL; + spin_lock_bh(&orig_node->vlan_list_lock); /* first look if an object for this vid already exists */ --- base-commit: c14c19af09d593a8948dcfd4a75ad6eef943ae3e change-id: 20240504-vlan_check-2c9c116102a1 Best regards, -- Sven Eckelmann <sven(a)narfation.org>

1 0

[PATCH v2] batman-adv: Add flex array to struct batadv_tvlv_tt_data
by Erick Archer 01 May '24

01 May '24

The "struct batadv_tvlv_tt_data" uses a dynamically sized set of trailing elements. Specifically, it uses an array of structures of type "batadv_tvlv_tt_vlan_data". So, use the preferred way in the kernel declaring a flexible array [1]. At the same time, prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions). In this case, it is important to note that the attribute used is specifically __counted_by_be since variable "num_vlan" is of type __be16. The order in which the structure batadv_tvlv_tt_data and the structure batadv_tvlv_tt_vlan_data are defined must be swap to avoid an incomplete type error. Also, avoid the open-coded arithmetic in memory allocator functions [2] using the "struct_size" macro and use the "flex_array_size" helper to clarify some calculations, when possible. Moreover, the new structure member also allow us to avoid the open-coded arithmetic on pointers in some situations. Take advantage of this. This code was detected with the help of Coccinelle, and audited and modified manually. Link: https://www.kernel.org/doc/html/next/process/deprecated.html#zero-length-an… [1] Link: https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-ari… [2] Signed-off-by: Erick Archer <erick.archer(a)outlook.com> --- Changes in v2: - Add the #include of <linux/overflow.h> for the "flex_array_size" helper (Sven Eckelmann). - Add the "ntohs" function to the "flex_array_size" helper removed by mistake during the conversion (Sven Eckelmann). - Add the "__counted_by_be" attribute. Previous versions: v1 -> https://lore.kernel.org/linux-hardening/AS8PR02MB7237987BF9DFCA030B330F658B… Hi, In this version I have worked on the "sparse" warnings. The difference in "sparse" warnings before and after this patch is as follows: net/batman-adv/translation-table.c:534:21: warning: using sizeof on a flexible structure net/batman-adv/translation-table.c:819:25: warning: expression using sizeof(void) net/batman-adv/translation-table.c:819:25: warning: using sizeof on a flexible structure net/batman-adv/translation-table.c:819:25: warning: expression using sizeof(void) net/batman-adv/translation-table.c:819:25: warning: using sizeof on a flexible structure net/batman-adv/translation-table.c:819:25: warning: expression using sizeof(void) net/batman-adv/translation-table.c:898:25: warning: expression using sizeof(void) net/batman-adv/translation-table.c:898:25: warning: using sizeof on a flexible structure net/batman-adv/translation-table.c:898:25: warning: expression using sizeof(void) net/batman-adv/translation-table.c:898:25: warning: using sizeof on a flexible structure net/batman-adv/translation-table.c:898:25: warning: expression using sizeof(void) net/batman-adv/translation-table.c:2892:16: warning: expression using sizeof(void) net/batman-adv/translation-table.c:2892:16: warning: using sizeof on a flexible structure net/batman-adv/translation-table.c:2892:16: warning: expression using sizeof(void) net/batman-adv/translation-table.c:2892:16: warning: using sizeof on a flexible structure net/batman-adv/translation-table.c:2892:16: warning: expression using sizeof(void) net/batman-adv/translation-table.c:3338:21: warning: expression using sizeof(void) net/batman-adv/translation-table.c:3338:21: warning: using sizeof on a flexible structure net/batman-adv/translation-table.c:3338:21: warning: expression using sizeof(void) net/batman-adv/translation-table.c:3338:21: warning: using sizeof on a flexible structure net/batman-adv/translation-table.c:3338:21: warning: expression using sizeof(void) net/batman-adv/translation-table.c:3942:30: warning: using sizeof on a flexible structure net/batman-adv/translation-table.c:3946:27: warning: using sizeof on a flexible structure net/batman-adv/translation-table.c:3950:21: warning: expression using sizeof(void) net/batman-adv/translation-table.c:3986:30: warning: using sizeof on a flexible structure net/batman-adv/translation-table.c:3990:27: warning: using sizeof on a flexible structure net/batman-adv/translation-table.c:3992:23: warning: expression using sizeof(void) As far as I know, these warnings cannot be removed. However it can be safely ignored since: Case 1: Warning "using sizeof on a flexible structure" The commit 1a88f2f24619 ("flex-array: warn when using sizeof() on a flexible array") in the sparse git repository says Using sizeof() on a structure containing a flexible array will ignore the 'flexible' part. This is maybe what is expected but maybe not, so add an option -Wflexible-array-sizeof to warn on such usage. In this patch we take care of using or ignoring the flexible part when necessary. Therefore, these warnings can be safely ignored. Case 2: Warning "expression using sizeof(void)" This warning is implied by the use of the "struct_size" helper and "flex_array_size" helper because they both use the "__is_constexpr" macro. And this macro is defined using "sizeof(void)". /* * This returns a constant expression while determining if an argument is * a constant expression, most importantly without evaluating the argument. * Glory to Martin Uecker <Martin.Uecker(a)med.uni-goettingen.de> * * Details: * - sizeof() return an integer constant expression, and does not evaluate * the value of its operand; it only examines the type of its operand. * - The results of comparing two integer constant expressions is also * an integer constant expression. * - The first literal "8" isn't important. It could be any literal value. * - The second literal "8" is to avoid warnings about unaligned pointers; * this could otherwise just be "1". * - (long)(x) is used to avoid warnings about 64-bit types on 32-bit * architectures. * - The C Standard defines "null pointer constant", "(void *)0", as * distinct from other void pointers. * - If (x) is an integer constant expression, then the "* 0l" resolves * it into an integer constant expression of value 0. Since it is cast to * "void *", this makes the second operand a null pointer constant. * - If (x) is not an integer constant expression, then the second operand * resolves to a void pointer (but not a null pointer constant: the value * is not an integer constant 0). * - The conditional operator's third operand, "(int *)8", is an object * pointer (to type "int"). * - The behavior (including the return type) of the conditional operator * ("operand1 ? operand2 : operand3") depends on the kind of expressions * given for the second and third operands. This is the central mechanism * of the macro: * - When one operand is a null pointer constant (i.e. when x is an integer * constant expression) and the other is an object pointer (i.e. our * third operand), the conditional operator returns the type of the * object pointer operand (i.e. "int *"). Here, within the sizeof(), we * would then get: * sizeof(*((int *)(...)) == sizeof(int) == 4 * - When one operand is a void pointer (i.e. when x is not an integer * constant expression) and the other is an object pointer (i.e. our * third operand), the conditional operator returns a "void *" type. * Here, within the sizeof(), we would then get: * sizeof(*((void *)(...)) == sizeof(void) == 1 * - The equality comparison to "sizeof(int)" therefore depends on (x): * sizeof(int) == sizeof(int) (x) was a constant expression * sizeof(int) != sizeof(void) (x) was not a constant expression */ #define __is_constexpr(x) \ (sizeof(int) == sizeof(*(8 ? ((void *)((long)(x) * 0l)) : (int *)8))) Therefore, these warnings can also be safely ignored. The Coccinelle script used to detect this code pattern is the following: virtual report @rule1@ type t1; type t2; identifier i0; identifier i1; identifier i2; identifier ALLOC =~ "kmalloc|kzalloc|kmalloc_node|kzalloc_node|vmalloc|vzalloc|kvmalloc|kvzalloc"; position p1; @@ i0 = sizeof(t1) + sizeof(t2) * i1; ... i2 = ALLOC@p1(..., i0, ...); @script:python depends on report@ p1 << rule1.p1; @@ msg = "WARNING: verify allocation on line %s" % (p1[0].line) coccilib.report.print_report(p1[0],msg) Regards, Erick --- include/uapi/linux/batadv_packet.h | 28 +++++++++-------- net/batman-adv/translation-table.c | 49 ++++++++++++------------------ 2 files changed, 35 insertions(+), 42 deletions(-) diff --git a/include/uapi/linux/batadv_packet.h b/include/uapi/linux/batadv_packet.h index 6e25753015df..dfbe30536995 100644 --- a/include/uapi/linux/batadv_packet.h +++ b/include/uapi/linux/batadv_packet.h @@ -592,19 +592,6 @@ struct batadv_tvlv_gateway_data { __be32 bandwidth_up; }; -/** - * struct batadv_tvlv_tt_data - tt data propagated through the tt tvlv container - * @flags: translation table flags (see batadv_tt_data_flags) - * @ttvn: translation table version number - * @num_vlan: number of announced VLANs. In the TVLV this struct is followed by - * one batadv_tvlv_tt_vlan_data object per announced vlan - */ -struct batadv_tvlv_tt_data { - __u8 flags; - __u8 ttvn; - __be16 num_vlan; -}; - /** * struct batadv_tvlv_tt_vlan_data - vlan specific tt data propagated through * the tt tvlv container @@ -618,6 +605,21 @@ struct batadv_tvlv_tt_vlan_data { __u16 reserved; }; +/** + * struct batadv_tvlv_tt_data - tt data propagated through the tt tvlv container + * @flags: translation table flags (see batadv_tt_data_flags) + * @ttvn: translation table version number + * @num_vlan: number of announced VLANs. In the TVLV this struct is followed by + * one batadv_tvlv_tt_vlan_data object per announced vlan + * @vlan_data: array of batadv_tvlv_tt_vlan_data objects + */ +struct batadv_tvlv_tt_data { + __u8 flags; + __u8 ttvn; + __be16 num_vlan; + struct batadv_tvlv_tt_vlan_data vlan_data[] __counted_by_be(num_vlan); +}; + /** * struct batadv_tvlv_tt_change - translation table diff data * @flags: status indicators concerning the non-mesh client (see diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c index b21ff3c36b07..d66fd900181c 100644 --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -28,6 +28,7 @@ #include <linux/net.h> #include <linux/netdevice.h> #include <linux/netlink.h> +#include <linux/overflow.h> #include <linux/rculist.h> #include <linux/rcupdate.h> #include <linux/skbuff.h> @@ -815,8 +816,7 @@ batadv_tt_prepare_tvlv_global_data(struct batadv_orig_node *orig_node, num_entries += atomic_read(&vlan->tt.num_entries); } - change_offset = sizeof(**tt_data); - change_offset += num_vlan * sizeof(*tt_vlan); + change_offset = struct_size(*tt_data, vlan_data, num_vlan); /* if tt_len is negative, allocate the space needed by the full table */ if (*tt_len < 0) @@ -835,7 +835,7 @@ batadv_tt_prepare_tvlv_global_data(struct batadv_orig_node *orig_node, (*tt_data)->ttvn = atomic_read(&orig_node->last_ttvn); (*tt_data)->num_vlan = htons(num_vlan); - tt_vlan = (struct batadv_tvlv_tt_vlan_data *)(*tt_data + 1); + tt_vlan = (*tt_data)->vlan_data; hlist_for_each_entry(vlan, &orig_node->vlan_list, list) { tt_vlan->vid = htons(vlan->vid); tt_vlan->crc = htonl(vlan->tt.crc); @@ -895,8 +895,7 @@ batadv_tt_prepare_tvlv_local_data(struct batadv_priv *bat_priv, total_entries += vlan_entries; } - change_offset = sizeof(**tt_data); - change_offset += num_vlan * sizeof(*tt_vlan); + change_offset = struct_size(*tt_data, vlan_data, num_vlan); /* if tt_len is negative, allocate the space needed by the full table */ if (*tt_len < 0) @@ -915,7 +914,7 @@ batadv_tt_prepare_tvlv_local_data(struct batadv_priv *bat_priv, (*tt_data)->ttvn = atomic_read(&bat_priv->tt.vn); (*tt_data)->num_vlan = htons(num_vlan); - tt_vlan = (struct batadv_tvlv_tt_vlan_data *)(*tt_data + 1); + tt_vlan = (*tt_data)->vlan_data; hlist_for_each_entry(vlan, &bat_priv->softif_vlan_list, list) { vlan_entries = atomic_read(&vlan->tt.num_entries); if (vlan_entries < 1) @@ -2875,7 +2874,6 @@ static bool batadv_send_tt_request(struct batadv_priv *bat_priv, { struct batadv_tvlv_tt_data *tvlv_tt_data = NULL; struct batadv_tt_req_node *tt_req_node = NULL; - struct batadv_tvlv_tt_vlan_data *tt_vlan_req; struct batadv_hard_iface *primary_if; bool ret = false; int i, size; @@ -2891,7 +2889,7 @@ static bool batadv_send_tt_request(struct batadv_priv *bat_priv, if (!tt_req_node) goto out; - size = sizeof(*tvlv_tt_data) + sizeof(*tt_vlan_req) * num_vlan; + size = struct_size(tvlv_tt_data, vlan_data, num_vlan); tvlv_tt_data = kzalloc(size, GFP_ATOMIC); if (!tvlv_tt_data) goto out; @@ -2903,12 +2901,10 @@ static bool batadv_send_tt_request(struct batadv_priv *bat_priv, /* send all the CRCs within the request. This is needed by intermediate * nodes to ensure they have the correct table before replying */ - tt_vlan_req = (struct batadv_tvlv_tt_vlan_data *)(tvlv_tt_data + 1); for (i = 0; i < num_vlan; i++) { - tt_vlan_req->vid = tt_vlan->vid; - tt_vlan_req->crc = tt_vlan->crc; + tvlv_tt_data->vlan_data[i].vid = tt_vlan->vid; + tvlv_tt_data->vlan_data[i].crc = tt_vlan->crc; - tt_vlan_req++; tt_vlan++; } @@ -2960,7 +2956,6 @@ static bool batadv_send_other_tt_response(struct batadv_priv *bat_priv, struct batadv_orig_node *res_dst_orig_node = NULL; struct batadv_tvlv_tt_change *tt_change; struct batadv_tvlv_tt_data *tvlv_tt_data = NULL; - struct batadv_tvlv_tt_vlan_data *tt_vlan; bool ret = false, full_table; u8 orig_ttvn, req_ttvn; u16 tvlv_len; @@ -2983,10 +2978,9 @@ static bool batadv_send_other_tt_response(struct batadv_priv *bat_priv, orig_ttvn = (u8)atomic_read(&req_dst_orig_node->last_ttvn); req_ttvn = tt_data->ttvn; - tt_vlan = (struct batadv_tvlv_tt_vlan_data *)(tt_data + 1); /* this node doesn't have the requested data */ if (orig_ttvn != req_ttvn || - !batadv_tt_global_check_crc(req_dst_orig_node, tt_vlan, + !batadv_tt_global_check_crc(req_dst_orig_node, tt_data->vlan_data, ntohs(tt_data->num_vlan))) goto out; @@ -3329,7 +3323,6 @@ static void batadv_handle_tt_response(struct batadv_priv *bat_priv, struct batadv_orig_node *orig_node = NULL; struct batadv_tvlv_tt_change *tt_change; u8 *tvlv_ptr = (u8 *)tt_data; - u16 change_offset; batadv_dbg(BATADV_DBG_TT, bat_priv, "Received TT_RESPONSE from %pM for ttvn %d t_size: %d [%c]\n", @@ -3342,10 +3335,7 @@ static void batadv_handle_tt_response(struct batadv_priv *bat_priv, spin_lock_bh(&orig_node->tt_lock); - change_offset = sizeof(struct batadv_tvlv_tt_vlan_data); - change_offset *= ntohs(tt_data->num_vlan); - change_offset += sizeof(*tt_data); - tvlv_ptr += change_offset; + tvlv_ptr += struct_size(tt_data, vlan_data, ntohs(tt_data->num_vlan)); tt_change = (struct batadv_tvlv_tt_change *)tvlv_ptr; if (tt_data->flags & BATADV_TT_FULL_TABLE) { @@ -3944,10 +3934,10 @@ static void batadv_tt_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv, u8 flags, void *tvlv_value, u16 tvlv_value_len) { - struct batadv_tvlv_tt_vlan_data *tt_vlan; struct batadv_tvlv_tt_change *tt_change; struct batadv_tvlv_tt_data *tt_data; u16 num_entries, num_vlan; + size_t flex_size; if (tvlv_value_len < sizeof(*tt_data)) return; @@ -3957,17 +3947,18 @@ static void batadv_tt_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv, num_vlan = ntohs(tt_data->num_vlan); - if (tvlv_value_len < sizeof(*tt_vlan) * num_vlan) + flex_size = flex_array_size(tt_data, vlan_data, num_vlan); + if (tvlv_value_len < flex_size) return; - tt_vlan = (struct batadv_tvlv_tt_vlan_data *)(tt_data + 1); - tt_change = (struct batadv_tvlv_tt_change *)(tt_vlan + num_vlan); - tvlv_value_len -= sizeof(*tt_vlan) * num_vlan; + tt_change = (struct batadv_tvlv_tt_change *)(tt_data->vlan_data + + num_vlan); + tvlv_value_len -= flex_size; num_entries = batadv_tt_entries(tvlv_value_len); - batadv_tt_update_orig(bat_priv, orig, tt_vlan, num_vlan, tt_change, - num_entries, tt_data->ttvn); + batadv_tt_update_orig(bat_priv, orig, tt_data->vlan_data, num_vlan, + tt_change, num_entries, tt_data->ttvn); } /** @@ -3998,8 +3989,8 @@ static int batadv_tt_tvlv_unicast_handler_v1(struct batadv_priv *bat_priv, tt_data = tvlv_value; tvlv_value_len -= sizeof(*tt_data); - tt_vlan_len = sizeof(struct batadv_tvlv_tt_vlan_data); - tt_vlan_len *= ntohs(tt_data->num_vlan); + tt_vlan_len = flex_array_size(tt_data, vlan_data, + ntohs(tt_data->num_vlan)); if (tvlv_value_len < tt_vlan_len) return NET_RX_SUCCESS; -- 2.25.1

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B.A.T.M.A.N May 2024