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eventfs: Use kcalloc() instead of kzalloc()

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As noted in the "Deprecated Interfaces, Language Features, Attributes,
and Conventions" documentation [1], size calculations (especially
multiplication) should not be performed in memory allocator (or similar)
function arguments due to the risk of them overflowing. This could lead
to values wrapping around and a smaller allocation being made than the
caller was expecting. Using those allocations could lead to linear
overflows of heap memory and other misbehaviors.

So, use the purpose specific kcalloc() function instead of the argument
size * count in the kzalloc() function.

[1] https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments

Link: https://lore.kernel.org/linux-trace-kernel/20240115181658.4562-1-erick.archer@gmx.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://github.com/KSPP/linux/issues/162
Signed-off-by: Erick Archer <erick.archer@gmx.com>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
This commit is contained in:
Erick Archer 2024-01-15 19:16:58 +01:00 committed by Steven Rostedt (Google)
parent 852e46e239
commit 1057066009
1 changed files with 3 additions and 3 deletions
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6
fs/tracefs/event_inode.c
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@ -97,7 +97,7 @@ static int eventfs_set_attr(struct mnt_idmap *idmap, struct dentry *dentry,
/* Preallocate the children mode array if necessary */
if (!(dentry->d_inode->i_mode & S_IFDIR)) {
if (!ei->entry_attrs) {
ei->entry_attrs = kzalloc(sizeof(*ei->entry_attrs) * ei->nr_entries,
ei->entry_attrs = kcalloc(ei->nr_entries, sizeof(*ei->entry_attrs),
GFP_NOFS);
if (!ei->entry_attrs) {
ret = -ENOMEM;
@ -874,7 +874,7 @@ struct eventfs_inode *eventfs_create_dir(const char *name, struct eventfs_inode
}
if (size) {
ei->d_children = kzalloc(sizeof(*ei->d_children) * size, GFP_KERNEL);
ei->d_children = kcalloc(size, sizeof(*ei->d_children), GFP_KERNEL);
if (!ei->d_children) {
kfree_const(ei->name);
kfree(ei);
@ -941,7 +941,7 @@ struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry
goto fail;
if (size) {
ei->d_children = kzalloc(sizeof(*ei->d_children) * size, GFP_KERNEL);
ei->d_children = kcalloc(size, sizeof(*ei->d_children), GFP_KERNEL);
if (!ei->d_children)
goto fail;
}