Messages in this thread | ![/](/images/icornerl.gif) | | Date | Tue, 14 Dec 2021 11:54:48 -0600 | From | "Gustavo A. R. Silva" <> | Subject | Re: [PATCH -next] audit: use struct_size() helper in kmalloc() |
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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 > @@ -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 > @@ -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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