From 50d7bd38c3aafc4749e05e8d7fcb616979143602 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Mon, 17 May 2021 20:01:15 -0700 Subject: stddef: Introduce struct_group() helper macro Kernel code has a regular need to describe groups of members within a structure usually when they need to be copied or initialized separately from the rest of the surrounding structure. The generally accepted design pattern in C is to use a named sub-struct: struct foo { int one; struct { int two; int three, four; } thing; int five; }; This would allow for traditional references and sizing: memcpy(&dst.thing, &src.thing, sizeof(dst.thing)); However, doing this would mean that referencing struct members enclosed by such named structs would always require including the sub-struct name in identifiers: do_something(dst.thing.three); This has tended to be quite inflexible, especially when such groupings need to be added to established code which causes huge naming churn. Three workarounds exist in the kernel for this problem, and each have other negative properties. To avoid the naming churn, there is a design pattern of adding macro aliases for the named struct: #define f_three thing.three This ends up polluting the global namespace, and makes it difficult to search for identifiers. Another common work-around in kernel code avoids the pollution by avoiding the named struct entirely, instead identifying the group's boundaries using either a pair of empty anonymous structs of a pair of zero-element arrays: struct foo { int one; struct { } start; int two; int three, four; struct { } finish; int five; }; struct foo { int one; int start[0]; int two; int three, four; int finish[0]; int five; }; This allows code to avoid needing to use a sub-struct named for member references within the surrounding structure, but loses the benefits of being able to actually use such a struct, making it rather fragile. Using these requires open-coded calculation of sizes and offsets. The efforts made to avoid common mistakes include lots of comments, or adding various BUILD_BUG_ON()s. Such code is left with no way for the compiler to reason about the boundaries (e.g. the "start" object looks like it's 0 bytes in length), making bounds checking depend on open-coded calculations: if (length > offsetof(struct foo, finish) - offsetof(struct foo, start)) return -EINVAL; memcpy(&dst.start, &src.start, offsetof(struct foo, finish) - offsetof(struct foo, start)); However, the vast majority of places in the kernel that operate on groups of members do so without any identification of the grouping, relying either on comments or implicit knowledge of the struct contents, which is even harder for the compiler to reason about, and results in even more fragile manual sizing, usually depending on member locations outside of the region (e.g. to copy "two" and "three", use the start of "four" to find the size): BUILD_BUG_ON((offsetof(struct foo, four) < offsetof(struct foo, two)) || (offsetof(struct foo, four) < offsetof(struct foo, three)); if (length > offsetof(struct foo, four) - offsetof(struct foo, two)) return -EINVAL; memcpy(&dst.two, &src.two, length); In order to have a regular programmatic way to describe a struct region that can be used for references and sizing, can be examined for bounds checking, avoids forcing the use of intermediate identifiers, and avoids polluting the global namespace, introduce the struct_group() macro. This macro wraps the member declarations to create an anonymous union of an anonymous struct (no intermediate name) and a named struct (for references and sizing): struct foo { int one; struct_group(thing, int two; int three, four; ); int five; }; if (length > sizeof(src.thing)) return -EINVAL; memcpy(&dst.thing, &src.thing, length); do_something(dst.three); There are some rare cases where the resulting struct_group() needs attributes added, so struct_group_attr() is also introduced to allow for specifying struct attributes (e.g. __align(x) or __packed). Additionally, there are places where such declarations would like to have the struct be tagged, so struct_group_tagged() is added. Given there is a need for a handful of UAPI uses too, the underlying __struct_group() macro has been defined in UAPI so it can be used there too. To avoid confusing scripts/kernel-doc, hide the macro from its struct parsing. Co-developed-by: Keith Packard Signed-off-by: Keith Packard Acked-by: Gustavo A. R. Silva Link: https://lore.kernel.org/lkml/20210728023217.GC35706@embeddedor Enhanced-by: Rasmus Villemoes Link: https://lore.kernel.org/lkml/41183a98-bdb9-4ad6-7eab-5a7292a6df84@rasmusvillemoes.dk Enhanced-by: Dan Williams Link: https://lore.kernel.org/lkml/1d9a2e6df2a9a35b2cdd50a9a68cac5991e7e5f0.camel@intel.com Enhanced-by: Daniel Vetter Link: https://lore.kernel.org/lkml/YQKa76A6XuFqgM03@phenom.ffwll.local Acked-by: Dan Williams Signed-off-by: Kees Cook --- include/uapi/linux/stddef.h | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'include/uapi') diff --git a/include/uapi/linux/stddef.h b/include/uapi/linux/stddef.h index ee8220f8dcf5..610204f7c275 100644 --- a/include/uapi/linux/stddef.h +++ b/include/uapi/linux/stddef.h @@ -4,3 +4,24 @@ #ifndef __always_inline #define __always_inline inline #endif + +/** + * __struct_group() - Create a mirrored named and anonyomous struct + * + * @TAG: The tag name for the named sub-struct (usually empty) + * @NAME: The identifier name of the mirrored sub-struct + * @ATTRS: Any struct attributes (usually empty) + * @MEMBERS: The member declarations for the mirrored structs + * + * Used to create an anonymous union of two structs with identical layout + * and size: one anonymous and one named. The former's members can be used + * normally without sub-struct naming, and the latter can be used to + * reason about the start, end, and size of the group of struct members. + * The named struct can also be explicitly tagged for layer reuse, as well + * as both having struct attributes appended. + */ +#define __struct_group(TAG, NAME, ATTRS, MEMBERS...) \ + union { \ + struct { MEMBERS } ATTRS; \ + struct TAG { MEMBERS } ATTRS NAME; \ + } -- cgit v1.2.3 From 10579b75e02362809e8db610f3160f520607b395 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Mon, 24 May 2021 23:55:11 -0700 Subject: drm/mga/mga_ioc32: Use struct_group() for memcpy() region In preparation for FORTIFY_SOURCE performing compile-time and run-time field bounds checking for memcpy(), memmove(), and memset(), avoid intentionally writing across neighboring fields. Use struct_group() in struct drm32_mga_init around members chipset, sgram, maccess, fb_cpp, front_offset, front_pitch, back_offset, back_pitch, depth_cpp, depth_offset, depth_pitch, texture_offset, and texture_size, so they can be referenced together. This will allow memcpy() and sizeof() to more easily reason about sizes, improve readability, and avoid future warnings about writing beyond the end of chipset. "pahole" shows no size nor member offset changes to struct drm32_mga_init. "objdump -d" shows no meaningful object code changes (i.e. only source line number induced differences and optimizations). Note that since this is a UAPI header, __struct_group() is used directly. Cc: David Airlie Cc: Lee Jones Cc: dri-devel@lists.freedesktop.org Signed-off-by: Kees Cook Acked-by: Daniel Vetter Link: https://lore.kernel.org/lkml/YQKa76A6XuFqgM03@phenom.ffwll.local --- drivers/gpu/drm/mga/mga_ioc32.c | 27 ++++++++++++++------------- include/uapi/drm/mga_drm.h | 22 ++++++++++++---------- 2 files changed, 26 insertions(+), 23 deletions(-) (limited to 'include/uapi') diff --git a/drivers/gpu/drm/mga/mga_ioc32.c b/drivers/gpu/drm/mga/mga_ioc32.c index 4fd4de16cd32..894472921c30 100644 --- a/drivers/gpu/drm/mga/mga_ioc32.c +++ b/drivers/gpu/drm/mga/mga_ioc32.c @@ -38,16 +38,18 @@ typedef struct drm32_mga_init { int func; u32 sarea_priv_offset; - int chipset; - int sgram; - unsigned int maccess; - unsigned int fb_cpp; - unsigned int front_offset, front_pitch; - unsigned int back_offset, back_pitch; - unsigned int depth_cpp; - unsigned int depth_offset, depth_pitch; - unsigned int texture_offset[MGA_NR_TEX_HEAPS]; - unsigned int texture_size[MGA_NR_TEX_HEAPS]; + struct_group(always32bit, + int chipset; + int sgram; + unsigned int maccess; + unsigned int fb_cpp; + unsigned int front_offset, front_pitch; + unsigned int back_offset, back_pitch; + unsigned int depth_cpp; + unsigned int depth_offset, depth_pitch; + unsigned int texture_offset[MGA_NR_TEX_HEAPS]; + unsigned int texture_size[MGA_NR_TEX_HEAPS]; + ); u32 fb_offset; u32 mmio_offset; u32 status_offset; @@ -67,9 +69,8 @@ static int compat_mga_init(struct file *file, unsigned int cmd, init.func = init32.func; init.sarea_priv_offset = init32.sarea_priv_offset; - memcpy(&init.chipset, &init32.chipset, - offsetof(drm_mga_init_t, fb_offset) - - offsetof(drm_mga_init_t, chipset)); + memcpy(&init.always32bit, &init32.always32bit, + sizeof(init32.always32bit)); init.fb_offset = init32.fb_offset; init.mmio_offset = init32.mmio_offset; init.status_offset = init32.status_offset; diff --git a/include/uapi/drm/mga_drm.h b/include/uapi/drm/mga_drm.h index 8c4337548ab5..bb31567e66c0 100644 --- a/include/uapi/drm/mga_drm.h +++ b/include/uapi/drm/mga_drm.h @@ -279,20 +279,22 @@ typedef struct drm_mga_init { unsigned long sarea_priv_offset; - int chipset; - int sgram; + __struct_group(/* no tag */, always32bit, /* no attrs */, + int chipset; + int sgram; - unsigned int maccess; + unsigned int maccess; - unsigned int fb_cpp; - unsigned int front_offset, front_pitch; - unsigned int back_offset, back_pitch; + unsigned int fb_cpp; + unsigned int front_offset, front_pitch; + unsigned int back_offset, back_pitch; - unsigned int depth_cpp; - unsigned int depth_offset, depth_pitch; + unsigned int depth_cpp; + unsigned int depth_offset, depth_pitch; - unsigned int texture_offset[MGA_NR_TEX_HEAPS]; - unsigned int texture_size[MGA_NR_TEX_HEAPS]; + unsigned int texture_offset[MGA_NR_TEX_HEAPS]; + unsigned int texture_size[MGA_NR_TEX_HEAPS]; + ); unsigned long fb_offset; unsigned long mmio_offset; -- cgit v1.2.3 From 3080ea5553cc909b000d1f1d964a9041962f2c5b Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Mon, 9 Aug 2021 11:21:23 -0700 Subject: stddef: Introduce DECLARE_FLEX_ARRAY() helper There are many places where kernel code wants to have several different typed trailing flexible arrays. This would normally be done with multiple flexible arrays in a union, but since GCC and Clang don't (on the surface) allow this, there have been many open-coded workarounds, usually involving neighboring 0-element arrays at the end of a structure. For example, instead of something like this: struct thing { ... union { struct type1 foo[]; struct type2 bar[]; }; }; code works around the compiler with: struct thing { ... struct type1 foo[0]; struct type2 bar[]; }; Another case is when a flexible array is wanted as the single member within a struct (which itself is usually in a union). For example, this would be worked around as: union many { ... struct { struct type3 baz[0]; }; }; These kinds of work-arounds cause problems with size checks against such zero-element arrays (for example when building with -Warray-bounds and -Wzero-length-bounds, and with the coming FORTIFY_SOURCE improvements), so they must all be converted to "real" flexible arrays, avoiding warnings like this: fs/hpfs/anode.c: In function 'hpfs_add_sector_to_btree': fs/hpfs/anode.c:209:27: warning: array subscript 0 is outside the bounds of an interior zero-length array 'struct bplus_internal_node[0]' [-Wzero-length-bounds] 209 | anode->btree.u.internal[0].down = cpu_to_le32(a); | ~~~~~~~~~~~~~~~~~~~~~~~^~~ In file included from fs/hpfs/hpfs_fn.h:26, from fs/hpfs/anode.c:10: fs/hpfs/hpfs.h:412:32: note: while referencing 'internal' 412 | struct bplus_internal_node internal[0]; /* (internal) 2-word entries giving | ^~~~~~~~ drivers/net/can/usb/etas_es58x/es58x_fd.c: In function 'es58x_fd_tx_can_msg': drivers/net/can/usb/etas_es58x/es58x_fd.c:360:35: warning: array subscript 65535 is outside the bounds of an interior zero-length array 'u8[0]' {aka 'unsigned char[]'} [-Wzero-length-bounds] 360 | tx_can_msg = (typeof(tx_can_msg))&es58x_fd_urb_cmd->raw_msg[msg_len]; | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from drivers/net/can/usb/etas_es58x/es58x_core.h:22, from drivers/net/can/usb/etas_es58x/es58x_fd.c:17: drivers/net/can/usb/etas_es58x/es58x_fd.h:231:6: note: while referencing 'raw_msg' 231 | u8 raw_msg[0]; | ^~~~~~~ However, it _is_ entirely possible to have one or more flexible arrays in a struct or union: it just has to be in another struct. And since it cannot be alone in a struct, such a struct must have at least 1 other named member -- but that member can be zero sized. Wrap all this nonsense into the new DECLARE_FLEX_ARRAY() in support of having flexible arrays in unions (or alone in a struct). As with struct_group(), since this is needed in UAPI headers as well, implement the core there, with a non-UAPI wrapper. Additionally update kernel-doc to understand its existence. https://github.com/KSPP/linux/issues/137 Cc: Arnd Bergmann Cc: "Gustavo A. R. Silva" Signed-off-by: Kees Cook --- include/linux/stddef.h | 13 +++++++++++++ include/uapi/linux/stddef.h | 16 ++++++++++++++++ scripts/kernel-doc | 2 ++ 3 files changed, 31 insertions(+) (limited to 'include/uapi') diff --git a/include/linux/stddef.h b/include/linux/stddef.h index 8b103a53b000..ca507bd5f808 100644 --- a/include/linux/stddef.h +++ b/include/linux/stddef.h @@ -84,4 +84,17 @@ enum { #define struct_group_tagged(TAG, NAME, MEMBERS...) \ __struct_group(TAG, NAME, /* no attrs */, MEMBERS) +/** + * DECLARE_FLEX_ARRAY() - Declare a flexible array usable in a union + * + * @TYPE: The type of each flexible array element + * @NAME: The name of the flexible array member + * + * In order to have a flexible array member in a union or alone in a + * struct, it needs to be wrapped in an anonymous struct with at least 1 + * named member, but that member can be empty. + */ +#define DECLARE_FLEX_ARRAY(TYPE, NAME) \ + __DECLARE_FLEX_ARRAY(TYPE, NAME) + #endif diff --git a/include/uapi/linux/stddef.h b/include/uapi/linux/stddef.h index 610204f7c275..3021ea25a284 100644 --- a/include/uapi/linux/stddef.h +++ b/include/uapi/linux/stddef.h @@ -25,3 +25,19 @@ struct { MEMBERS } ATTRS; \ struct TAG { MEMBERS } ATTRS NAME; \ } + +/** + * __DECLARE_FLEX_ARRAY() - Declare a flexible array usable in a union + * + * @TYPE: The type of each flexible array element + * @NAME: The name of the flexible array member + * + * In order to have a flexible array member in a union or alone in a + * struct, it needs to be wrapped in an anonymous struct with at least 1 + * named member, but that member can be empty. + */ +#define __DECLARE_FLEX_ARRAY(TYPE, NAME) \ + struct { \ + struct { } __empty_ ## NAME; \ + TYPE NAME[]; \ + } diff --git a/scripts/kernel-doc b/scripts/kernel-doc index 38aa799a776c..5d54b57ff90c 100755 --- a/scripts/kernel-doc +++ b/scripts/kernel-doc @@ -1263,6 +1263,8 @@ sub dump_struct($$) { $members =~ s/DECLARE_KFIFO\s*\($args,\s*$args,\s*$args\)/$2 \*$1/gos; # replace DECLARE_KFIFO_PTR $members =~ s/DECLARE_KFIFO_PTR\s*\($args,\s*$args\)/$2 \*$1/gos; + # replace DECLARE_FLEX_ARRAY + $members =~ s/(?:__)?DECLARE_FLEX_ARRAY\s*\($args,\s*$args\)/$1 $2\[\]/gos; my $declaration = $members; # Split nested struct/union elements as newer ones -- cgit v1.2.3 From fa7845cfd53f3b1d3f60efa55db89805595bc045 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Mon, 9 Aug 2021 11:29:33 -0700 Subject: treewide: Replace open-coded flex arrays in unions In support of enabling -Warray-bounds and -Wzero-length-bounds and correctly handling run-time memcpy() bounds checking, replace all open-coded flexible arrays (i.e. 0-element arrays) in unions with the DECLARE_FLEX_ARRAY() helper macro. This fixes warnings such as: fs/hpfs/anode.c: In function 'hpfs_add_sector_to_btree': fs/hpfs/anode.c:209:27: warning: array subscript 0 is outside the bounds of an interior zero-length array 'struct bplus_internal_node[0]' [-Wzero-length-bounds] 209 | anode->btree.u.internal[0].down = cpu_to_le32(a); | ~~~~~~~~~~~~~~~~~~~~~~~^~~ In file included from fs/hpfs/hpfs_fn.h:26, from fs/hpfs/anode.c:10: fs/hpfs/hpfs.h:412:32: note: while referencing 'internal' 412 | struct bplus_internal_node internal[0]; /* (internal) 2-word entries giving | ^~~~~~~~ drivers/net/can/usb/etas_es58x/es58x_fd.c: In function 'es58x_fd_tx_can_msg': drivers/net/can/usb/etas_es58x/es58x_fd.c:360:35: warning: array subscript 65535 is outside the bounds of an interior zero-length array 'u8[0]' {aka 'unsigned char[]'} [-Wzero-length-bounds] 360 | tx_can_msg = (typeof(tx_can_msg))&es58x_fd_urb_cmd->raw_msg[msg_len]; | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from drivers/net/can/usb/etas_es58x/es58x_core.h:22, from drivers/net/can/usb/etas_es58x/es58x_fd.c:17: drivers/net/can/usb/etas_es58x/es58x_fd.h:231:6: note: while referencing 'raw_msg' 231 | u8 raw_msg[0]; | ^~~~~~~ Cc: "Gustavo A. R. Silva" Cc: Arnd Bergmann Cc: Ayush Sawal Cc: Vinay Kumar Yadav Cc: Rohit Maheshwari Cc: Herbert Xu Cc: "David S. Miller" Cc: Kalle Valo Cc: Jakub Kicinski Cc: Stanislaw Gruszka Cc: Luca Coelho Cc: "James E.J. Bottomley" Cc: "Martin K. Petersen" Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: Andrii Nakryiko Cc: Martin KaFai Lau Cc: Song Liu Cc: Yonghong Song Cc: John Fastabend Cc: KP Singh Cc: Johannes Berg Cc: Mordechay Goodstein Cc: Lee Jones Cc: Wolfgang Grandegger Cc: Marc Kleine-Budde Cc: Arunachalam Santhanam Cc: Vincent Mailhol Cc: Mikulas Patocka Cc: linux-crypto@vger.kernel.org Cc: ath10k@lists.infradead.org Cc: linux-wireless@vger.kernel.org Cc: netdev@vger.kernel.org Cc: linux-scsi@vger.kernel.org Cc: linux-can@vger.kernel.org Cc: bpf@vger.kernel.org Acked-by: Marc Kleine-Budde # drivers/net/can/usb/etas_es58x/* Signed-off-by: Kees Cook --- drivers/crypto/chelsio/chcr_crypto.h | 14 +++++++++----- drivers/net/can/usb/etas_es58x/es581_4.h | 2 +- drivers/net/can/usb/etas_es58x/es58x_fd.h | 2 +- drivers/net/wireless/ath/ath10k/htt.h | 7 +++++-- drivers/net/wireless/intel/iwlegacy/commands.h | 6 ++++-- drivers/net/wireless/intel/iwlwifi/dvm/commands.h | 6 ++++-- drivers/net/wireless/intel/iwlwifi/fw/api/tx.h | 12 ++++++++---- drivers/scsi/aic94xx/aic94xx_sds.c | 6 ++++-- fs/hpfs/hpfs.h | 8 ++++---- include/linux/filter.h | 6 ++++-- include/scsi/sas.h | 12 ++++++++---- include/uapi/rdma/rdma_user_rxe.h | 4 ++-- include/uapi/sound/asoc.h | 4 ++-- 13 files changed, 56 insertions(+), 33 deletions(-) (limited to 'include/uapi') diff --git a/drivers/crypto/chelsio/chcr_crypto.h b/drivers/crypto/chelsio/chcr_crypto.h index e89f9e0094b4..c7816c83e324 100644 --- a/drivers/crypto/chelsio/chcr_crypto.h +++ b/drivers/crypto/chelsio/chcr_crypto.h @@ -222,8 +222,10 @@ struct chcr_authenc_ctx { }; struct __aead_ctx { - struct chcr_gcm_ctx gcm[0]; - struct chcr_authenc_ctx authenc[]; + union { + DECLARE_FLEX_ARRAY(struct chcr_gcm_ctx, gcm); + DECLARE_FLEX_ARRAY(struct chcr_authenc_ctx, authenc); + }; }; struct chcr_aead_ctx { @@ -245,9 +247,11 @@ struct hmac_ctx { }; struct __crypto_ctx { - struct hmac_ctx hmacctx[0]; - struct ablk_ctx ablkctx[0]; - struct chcr_aead_ctx aeadctx[]; + union { + DECLARE_FLEX_ARRAY(struct hmac_ctx, hmacctx); + DECLARE_FLEX_ARRAY(struct ablk_ctx, ablkctx); + DECLARE_FLEX_ARRAY(struct chcr_aead_ctx, aeadctx); + }; }; struct chcr_context { diff --git a/drivers/net/can/usb/etas_es58x/es581_4.h b/drivers/net/can/usb/etas_es58x/es581_4.h index 4bc60a6df697..667ecb77168c 100644 --- a/drivers/net/can/usb/etas_es58x/es581_4.h +++ b/drivers/net/can/usb/etas_es58x/es581_4.h @@ -192,7 +192,7 @@ struct es581_4_urb_cmd { struct es581_4_rx_cmd_ret rx_cmd_ret; __le64 timestamp; u8 rx_cmd_ret_u8; - u8 raw_msg[0]; + DECLARE_FLEX_ARRAY(u8, raw_msg); } __packed; __le16 reserved_for_crc16_do_not_use; diff --git a/drivers/net/can/usb/etas_es58x/es58x_fd.h b/drivers/net/can/usb/etas_es58x/es58x_fd.h index a191891b8777..c4b19a6a33ae 100644 --- a/drivers/net/can/usb/etas_es58x/es58x_fd.h +++ b/drivers/net/can/usb/etas_es58x/es58x_fd.h @@ -219,7 +219,7 @@ struct es58x_fd_urb_cmd { struct es58x_fd_tx_ack_msg tx_ack_msg; __le64 timestamp; __le32 rx_cmd_ret_le32; - u8 raw_msg[0]; + DECLARE_FLEX_ARRAY(u8, raw_msg); } __packed; __le16 reserved_for_crc16_do_not_use; diff --git a/drivers/net/wireless/ath/ath10k/htt.h b/drivers/net/wireless/ath/ath10k/htt.h index ec689e3ce48a..a6de08d3bf4a 100644 --- a/drivers/net/wireless/ath/ath10k/htt.h +++ b/drivers/net/wireless/ath/ath10k/htt.h @@ -1674,8 +1674,11 @@ struct htt_tx_fetch_ind { __le32 token; __le16 num_resp_ids; __le16 num_records; - __le32 resp_ids[0]; /* ath10k_htt_get_tx_fetch_ind_resp_ids() */ - struct htt_tx_fetch_record records[]; + union { + /* ath10k_htt_get_tx_fetch_ind_resp_ids() */ + DECLARE_FLEX_ARRAY(__le32, resp_ids); + DECLARE_FLEX_ARRAY(struct htt_tx_fetch_record, records); + }; } __packed; static inline void * diff --git a/drivers/net/wireless/intel/iwlegacy/commands.h b/drivers/net/wireless/intel/iwlegacy/commands.h index 89c6671b32bc..4a97310f8fee 100644 --- a/drivers/net/wireless/intel/iwlegacy/commands.h +++ b/drivers/net/wireless/intel/iwlegacy/commands.h @@ -1408,8 +1408,10 @@ struct il3945_tx_cmd { * MAC header goes here, followed by 2 bytes padding if MAC header * length is 26 or 30 bytes, followed by payload data */ - u8 payload[0]; - struct ieee80211_hdr hdr[]; + union { + DECLARE_FLEX_ARRAY(u8, payload); + DECLARE_FLEX_ARRAY(struct ieee80211_hdr, hdr); + }; } __packed; /* diff --git a/drivers/net/wireless/intel/iwlwifi/dvm/commands.h b/drivers/net/wireless/intel/iwlwifi/dvm/commands.h index 235c7a2e3483..75a4b8e26232 100644 --- a/drivers/net/wireless/intel/iwlwifi/dvm/commands.h +++ b/drivers/net/wireless/intel/iwlwifi/dvm/commands.h @@ -1251,8 +1251,10 @@ struct iwl_tx_cmd { * MAC header goes here, followed by 2 bytes padding if MAC header * length is 26 or 30 bytes, followed by payload data */ - u8 payload[0]; - struct ieee80211_hdr hdr[]; + union { + DECLARE_FLEX_ARRAY(u8, payload); + DECLARE_FLEX_ARRAY(struct ieee80211_hdr, hdr); + }; } __packed; /* diff --git a/drivers/net/wireless/intel/iwlwifi/fw/api/tx.h b/drivers/net/wireless/intel/iwlwifi/fw/api/tx.h index 24e4a82a55da..5fddfd391941 100644 --- a/drivers/net/wireless/intel/iwlwifi/fw/api/tx.h +++ b/drivers/net/wireless/intel/iwlwifi/fw/api/tx.h @@ -239,8 +239,10 @@ struct iwl_tx_cmd { u8 tid_tspec; __le16 pm_frame_timeout; __le16 reserved4; - u8 payload[0]; - struct ieee80211_hdr hdr[0]; + union { + DECLARE_FLEX_ARRAY(u8, payload); + DECLARE_FLEX_ARRAY(struct ieee80211_hdr, hdr); + }; } __packed; /* TX_CMD_API_S_VER_6 */ struct iwl_dram_sec_info { @@ -713,8 +715,10 @@ struct iwl_mvm_compressed_ba_notif { __le32 tx_rate; __le16 tfd_cnt; __le16 ra_tid_cnt; - struct iwl_mvm_compressed_ba_ratid ra_tid[0]; - struct iwl_mvm_compressed_ba_tfd tfd[]; + union { + DECLARE_FLEX_ARRAY(struct iwl_mvm_compressed_ba_ratid, ra_tid); + DECLARE_FLEX_ARRAY(struct iwl_mvm_compressed_ba_tfd, tfd); + }; } __packed; /* COMPRESSED_BA_RES_API_S_VER_4 */ /** diff --git a/drivers/scsi/aic94xx/aic94xx_sds.c b/drivers/scsi/aic94xx/aic94xx_sds.c index 46815e65f7a4..5def83c88f13 100644 --- a/drivers/scsi/aic94xx/aic94xx_sds.c +++ b/drivers/scsi/aic94xx/aic94xx_sds.c @@ -517,8 +517,10 @@ struct asd_ms_conn_map { u8 num_nodes; u8 usage_model_id; u32 _resvd; - struct asd_ms_conn_desc conn_desc[0]; - struct asd_ms_node_desc node_desc[]; + union { + DECLARE_FLEX_ARRAY(struct asd_ms_conn_desc, conn_desc); + DECLARE_FLEX_ARRAY(struct asd_ms_node_desc, node_desc); + }; } __attribute__ ((packed)); struct asd_ctrla_phy_entry { diff --git a/fs/hpfs/hpfs.h b/fs/hpfs/hpfs.h index d92c4af3e1b4..281dec8f636b 100644 --- a/fs/hpfs/hpfs.h +++ b/fs/hpfs/hpfs.h @@ -409,10 +409,10 @@ struct bplus_header __le16 first_free; /* offset from start of header to first free node in array */ union { - struct bplus_internal_node internal[0]; /* (internal) 2-word entries giving - subtree pointers */ - struct bplus_leaf_node external[0]; /* (external) 3-word entries giving - sector runs */ + /* (internal) 2-word entries giving subtree pointers */ + DECLARE_FLEX_ARRAY(struct bplus_internal_node, internal); + /* (external) 3-word entries giving sector runs */ + DECLARE_FLEX_ARRAY(struct bplus_leaf_node, external); } u; }; diff --git a/include/linux/filter.h b/include/linux/filter.h index 4a93c12543ee..4298c5e428a3 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -586,8 +586,10 @@ struct bpf_prog { struct bpf_prog_aux *aux; /* Auxiliary fields */ struct sock_fprog_kern *orig_prog; /* Original BPF program */ /* Instructions for interpreter */ - struct sock_filter insns[0]; - struct bpf_insn insnsi[]; + union { + DECLARE_FLEX_ARRAY(struct sock_filter, insns); + DECLARE_FLEX_ARRAY(struct bpf_insn, insnsi); + }; }; struct sk_filter { diff --git a/include/scsi/sas.h b/include/scsi/sas.h index 4726c1bbec65..64154c1fed02 100644 --- a/include/scsi/sas.h +++ b/include/scsi/sas.h @@ -323,8 +323,10 @@ struct ssp_response_iu { __be32 sense_data_len; __be32 response_data_len; - u8 resp_data[0]; - u8 sense_data[]; + union { + DECLARE_FLEX_ARRAY(u8, resp_data); + DECLARE_FLEX_ARRAY(u8, sense_data); + }; } __attribute__ ((packed)); struct ssp_command_iu { @@ -554,8 +556,10 @@ struct ssp_response_iu { __be32 sense_data_len; __be32 response_data_len; - u8 resp_data[0]; - u8 sense_data[]; + union { + DECLARE_FLEX_ARRAY(u8, resp_data); + DECLARE_FLEX_ARRAY(u8, sense_data); + }; } __attribute__ ((packed)); struct ssp_command_iu { diff --git a/include/uapi/rdma/rdma_user_rxe.h b/include/uapi/rdma/rdma_user_rxe.h index e283c2220aba..7f44d54bb0ab 100644 --- a/include/uapi/rdma/rdma_user_rxe.h +++ b/include/uapi/rdma/rdma_user_rxe.h @@ -141,8 +141,8 @@ struct rxe_dma_info { __u32 sge_offset; __u32 reserved; union { - __u8 inline_data[0]; - struct rxe_sge sge[0]; + __DECLARE_FLEX_ARRAY(__u8, inline_data); + __DECLARE_FLEX_ARRAY(struct rxe_sge, sge); }; }; diff --git a/include/uapi/sound/asoc.h b/include/uapi/sound/asoc.h index da61398b1f8f..053949287ce8 100644 --- a/include/uapi/sound/asoc.h +++ b/include/uapi/sound/asoc.h @@ -240,8 +240,8 @@ struct snd_soc_tplg_vendor_array { struct snd_soc_tplg_private { __le32 size; /* in bytes of private data */ union { - char data[0]; - struct snd_soc_tplg_vendor_array array[0]; + __DECLARE_FLEX_ARRAY(char, data); + __DECLARE_FLEX_ARRAY(struct snd_soc_tplg_vendor_array, array); }; } __attribute__((packed)); -- cgit v1.2.3 From 47c662486cccf03e7062139d069b07ab0126ef59 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Fri, 13 Aug 2021 12:19:24 -0700 Subject: treewide: Replace 0-element memcpy() destinations with flexible arrays The 0-element arrays that are used as memcpy() destinations are actually flexible arrays. Adjust their structures accordingly so that memcpy() can better reason able their destination size (i.e. they need to be seen as "unknown" length rather than "zero"). In some cases, use of the DECLARE_FLEX_ARRAY() helper is needed when a flexible array is alone in a struct. Cc: "Gustavo A. R. Silva" Cc: Arnd Bergmann Cc: Kalle Valo Cc: "David S. Miller" Cc: Jakub Kicinski Cc: Nilesh Javali Cc: Manish Rangankar Cc: GR-QLogic-Storage-Upstream@marvell.com Cc: "James E.J. Bottomley" Cc: "Martin K. Petersen" Cc: Larry Finger Cc: Phillip Potter Cc: Greg Kroah-Hartman Cc: Florian Schilhabel Cc: Johannes Berg Cc: Christophe JAILLET Cc: Fabio Aiuto Cc: Ross Schmidt Cc: Marco Cesati Cc: ath10k@lists.infradead.org Cc: linux-wireless@vger.kernel.org Cc: netdev@vger.kernel.org Cc: linux-scsi@vger.kernel.org Cc: linux-staging@lists.linux.dev Signed-off-by: Kees Cook --- drivers/net/wireless/ath/ath10k/bmi.h | 10 ++++----- drivers/scsi/qla4xxx/ql4_def.h | 4 ++-- drivers/staging/r8188eu/include/ieee80211.h | 6 +++--- drivers/staging/rtl8712/ieee80211.h | 4 ++-- drivers/staging/rtl8723bs/include/ieee80211.h | 6 +++--- include/linux/ieee80211.h | 30 +++++++++++++-------------- include/uapi/linux/dlm_device.h | 4 ++-- 7 files changed, 32 insertions(+), 32 deletions(-) (limited to 'include/uapi') diff --git a/drivers/net/wireless/ath/ath10k/bmi.h b/drivers/net/wireless/ath/ath10k/bmi.h index f6fadcbdd86e..0685c0d2d4ea 100644 --- a/drivers/net/wireless/ath/ath10k/bmi.h +++ b/drivers/net/wireless/ath/ath10k/bmi.h @@ -109,7 +109,7 @@ struct bmi_cmd { struct { __le32 addr; __le32 len; - u8 payload[0]; + u8 payload[]; } write_mem; struct { __le32 addr; @@ -138,18 +138,18 @@ struct bmi_cmd { } rompatch_uninstall; struct { __le32 count; - __le32 patch_ids[0]; /* length of @count */ + __le32 patch_ids[]; /* length of @count */ } rompatch_activate; struct { __le32 count; - __le32 patch_ids[0]; /* length of @count */ + __le32 patch_ids[]; /* length of @count */ } rompatch_deactivate; struct { __le32 addr; } lz_start; struct { __le32 len; /* max BMI_MAX_DATA_SIZE */ - u8 payload[0]; /* length of @len */ + u8 payload[]; /* length of @len */ } lz_data; struct { u8 name[BMI_NVRAM_SEG_NAME_SZ]; @@ -160,7 +160,7 @@ struct bmi_cmd { union bmi_resp { struct { - u8 payload[0]; + DECLARE_FLEX_ARRAY(u8, payload); } read_mem; struct { __le32 result; diff --git a/drivers/scsi/qla4xxx/ql4_def.h b/drivers/scsi/qla4xxx/ql4_def.h index 031569c496e5..69a590546bf9 100644 --- a/drivers/scsi/qla4xxx/ql4_def.h +++ b/drivers/scsi/qla4xxx/ql4_def.h @@ -366,13 +366,13 @@ struct qla4_work_evt { struct { enum iscsi_host_event_code code; uint32_t data_size; - uint8_t data[0]; + uint8_t data[]; } aen; struct { uint32_t status; uint32_t pid; uint32_t data_size; - uint8_t data[0]; + uint8_t data[]; } ping; } u; }; diff --git a/drivers/staging/r8188eu/include/ieee80211.h b/drivers/staging/r8188eu/include/ieee80211.h index bc5b030e9c40..9204dd42f319 100644 --- a/drivers/staging/r8188eu/include/ieee80211.h +++ b/drivers/staging/r8188eu/include/ieee80211.h @@ -185,7 +185,7 @@ struct ieee_param { struct { u32 len; u8 reserved[32]; - u8 data[0]; + u8 data[]; } wpa_ie; struct { int command; @@ -198,7 +198,7 @@ struct ieee_param { u8 idx; u8 seq[8]; /* sequence counter (set: RX, get: TX) */ u16 key_len; - u8 key[0]; + u8 key[]; } crypt; #ifdef CONFIG_88EU_AP_MODE struct { @@ -210,7 +210,7 @@ struct ieee_param { } add_sta; struct { u8 reserved[2];/* for set max_num_sta */ - u8 buf[0]; + u8 buf[]; } bcn_ie; #endif diff --git a/drivers/staging/rtl8712/ieee80211.h b/drivers/staging/rtl8712/ieee80211.h index 61eff7c5746b..65ceaca9b51e 100644 --- a/drivers/staging/rtl8712/ieee80211.h +++ b/drivers/staging/rtl8712/ieee80211.h @@ -78,7 +78,7 @@ struct ieee_param { struct { u32 len; u8 reserved[32]; - u8 data[0]; + u8 data[]; } wpa_ie; struct { int command; @@ -91,7 +91,7 @@ struct ieee_param { u8 idx; u8 seq[8]; /* sequence counter (set: RX, get: TX) */ u16 key_len; - u8 key[0]; + u8 key[]; } crypt; } u; }; diff --git a/drivers/staging/rtl8723bs/include/ieee80211.h b/drivers/staging/rtl8723bs/include/ieee80211.h index d6236f5b069d..c11d7e2d2347 100644 --- a/drivers/staging/rtl8723bs/include/ieee80211.h +++ b/drivers/staging/rtl8723bs/include/ieee80211.h @@ -172,7 +172,7 @@ struct ieee_param { struct { u32 len; u8 reserved[32]; - u8 data[0]; + u8 data[]; } wpa_ie; struct{ int command; @@ -185,7 +185,7 @@ struct ieee_param { u8 idx; u8 seq[8]; /* sequence counter (set: RX, get: TX) */ u16 key_len; - u8 key[0]; + u8 key[]; } crypt; struct { u16 aid; @@ -196,7 +196,7 @@ struct ieee_param { } add_sta; struct { u8 reserved[2];/* for set max_num_sta */ - u8 buf[0]; + u8 buf[]; } bcn_ie; } u; }; diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h index 694264503119..ada3dd79cd08 100644 --- a/include/linux/ieee80211.h +++ b/include/linux/ieee80211.h @@ -1143,7 +1143,7 @@ struct ieee80211_mgmt { __le16 auth_transaction; __le16 status_code; /* possibly followed by Challenge text */ - u8 variable[0]; + u8 variable[]; } __packed auth; struct { __le16 reason_code; @@ -1152,26 +1152,26 @@ struct ieee80211_mgmt { __le16 capab_info; __le16 listen_interval; /* followed by SSID and Supported rates */ - u8 variable[0]; + u8 variable[]; } __packed assoc_req; struct { __le16 capab_info; __le16 status_code; __le16 aid; /* followed by Supported rates */ - u8 variable[0]; + u8 variable[]; } __packed assoc_resp, reassoc_resp; struct { __le16 capab_info; __le16 status_code; - u8 variable[0]; + u8 variable[]; } __packed s1g_assoc_resp, s1g_reassoc_resp; struct { __le16 capab_info; __le16 listen_interval; u8 current_ap[ETH_ALEN]; /* followed by SSID and Supported rates */ - u8 variable[0]; + u8 variable[]; } __packed reassoc_req; struct { __le16 reason_code; @@ -1182,11 +1182,11 @@ struct ieee80211_mgmt { __le16 capab_info; /* followed by some of SSID, Supported rates, * FH Params, DS Params, CF Params, IBSS Params, TIM */ - u8 variable[0]; + u8 variable[]; } __packed beacon; struct { /* only variable items: SSID, Supported rates */ - u8 variable[0]; + DECLARE_FLEX_ARRAY(u8, variable); } __packed probe_req; struct { __le64 timestamp; @@ -1194,7 +1194,7 @@ struct ieee80211_mgmt { __le16 capab_info; /* followed by some of SSID, Supported rates, * FH Params, DS Params, CF Params, IBSS Params */ - u8 variable[0]; + u8 variable[]; } __packed probe_resp; struct { u8 category; @@ -1203,16 +1203,16 @@ struct ieee80211_mgmt { u8 action_code; u8 dialog_token; u8 status_code; - u8 variable[0]; + u8 variable[]; } __packed wme_action; struct{ u8 action_code; - u8 variable[0]; + u8 variable[]; } __packed chan_switch; struct{ u8 action_code; struct ieee80211_ext_chansw_ie data; - u8 variable[0]; + u8 variable[]; } __packed ext_chan_switch; struct{ u8 action_code; @@ -1228,7 +1228,7 @@ struct ieee80211_mgmt { __le16 timeout; __le16 start_seq_num; /* followed by BA Extension */ - u8 variable[0]; + u8 variable[]; } __packed addba_req; struct{ u8 action_code; @@ -1244,11 +1244,11 @@ struct ieee80211_mgmt { } __packed delba; struct { u8 action_code; - u8 variable[0]; + u8 variable[]; } __packed self_prot; struct{ u8 action_code; - u8 variable[0]; + u8 variable[]; } __packed mesh_action; struct { u8 action; @@ -1292,7 +1292,7 @@ struct ieee80211_mgmt { u8 toa[6]; __le16 tod_error; __le16 toa_error; - u8 variable[0]; + u8 variable[]; } __packed ftm; struct { u8 action_code; diff --git a/include/uapi/linux/dlm_device.h b/include/uapi/linux/dlm_device.h index f880d2831160..e83954c69fff 100644 --- a/include/uapi/linux/dlm_device.h +++ b/include/uapi/linux/dlm_device.h @@ -45,13 +45,13 @@ struct dlm_lock_params { void __user *bastaddr; struct dlm_lksb __user *lksb; char lvb[DLM_USER_LVB_LEN]; - char name[0]; + char name[]; }; struct dlm_lspace_params { __u32 flags; __u32 minor; - char name[0]; + char name[]; }; struct dlm_purge_params { -- cgit v1.2.3