Messages in this thread | | | Subject | Re: [PATCH -next] audit: use struct_size() helper in kmalloc() | From | xiujianfeng <> | Date | Wed, 15 Dec 2021 10:55:03 +0800 |
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在 2021/12/15 2:10, Gustavo A. R. Silva 写道: > On Tue, Dec 14, 2021 at 11:54:48AM -0600, Gustavo A. R. Silva wrote: >> On Tue, Dec 14, 2021 at 07:48:54PM +0800, Xiu Jianfeng wrote: >>> Make use of struct_size() helper instead of an open-coded calucation. >>> >>> Link: https://github.com/KSPP/linux/issues/160 >>> Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> >>> --- >>> kernel/audit.c | 2 +- >>> kernel/audit_tree.c | 2 +- >>> kernel/auditfilter.c | 2 +- >>> 3 files changed, 3 insertions(+), 3 deletions(-) >>> >>> diff --git a/kernel/audit.c b/kernel/audit.c >>> index d4084751cfe6..f33028578c60 100644 >>> --- a/kernel/audit.c >>> +++ b/kernel/audit.c > This could use struct_size(), too: > > 1461 audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0, > 1462 sig_data, sizeof(*sig_data) + len); > >>> @@ -1446,7 +1446,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) >>> if (err) >>> return err; >>> } >>> - sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL); >>> + sig_data = kmalloc(struct_size(sig_data, ctx, len), GFP_KERNEL); >>> if (!sig_data) { >>> if (audit_sig_sid) >>> security_release_secctx(ctx, len); >>> diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c >>> index 72324afcffef..e7315d487163 100644 >>> --- a/kernel/audit_tree.c >>> +++ b/kernel/audit_tree.c >>> @@ -94,7 +94,7 @@ static struct audit_tree *alloc_tree(const char *s) >>> { >>> struct audit_tree *tree; >>> >>> - tree = kmalloc(sizeof(struct audit_tree) + strlen(s) + 1, GFP_KERNEL); >>> + tree = kmalloc(struct_size(tree, pathname, strlen(s) + 1), GFP_KERNEL); >>> if (tree) { >>> refcount_set(&tree->count, 1); >>> tree->goner = 0; >>> diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c >>> index 4173e771650c..19352820b274 100644 >>> --- a/kernel/auditfilter.c >>> +++ b/kernel/auditfilter.c > Also, in this same file the following piece of code could use > struct_size(), too: > > 1093 skb = audit_make_reply(seq, AUDIT_LIST_RULES, 0, 1, > 1094 data, > 1095 sizeof(*data) + data->buflen); > > Thanks > -- > Gustavo thanks, I missed these two places, I will add them in the v2 patch. >>> @@ -637,7 +637,7 @@ static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule) >>> void *bufp; >>> int i; >>> >>> - data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL); >>> + data = kmalloc(struct_size(data, buf, krule->buflen), GFP_KERNEL); >> Why don't you also transform the zero-length array in struct >> audit_rule_data into a flexible-array member: >> >> 508 struct audit_rule_data { >> 509 __u32 flags; /* AUDIT_PER_{TASK,CALL}, AUDIT_PREPEND */ >> 510 __u32 action; /* AUDIT_NEVER, AUDIT_POSSIBLE, AUDIT_ALWAYS */ >> 511 __u32 field_count; >> 512 __u32 mask[AUDIT_BITMASK_SIZE]; /* syscall(s) affected */ >> 513 __u32 fields[AUDIT_MAX_FIELDS]; >> 514 __u32 values[AUDIT_MAX_FIELDS]; >> 515 __u32 fieldflags[AUDIT_MAX_FIELDS]; >> 516 __u32 buflen; /* total length of string fields */ >> 517 char buf[0]; /* string fields buffer */ >> 518 }; >> >> Thanks >> -- >> Gustavo >> >>> if (unlikely(!data)) >>> return NULL; >>> memset(data, 0, sizeof(*data)); >>> -- >>> 2.17.1 >>> >>> >>> >>> > .
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