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| author |   Len Baker <len.baker@gmx.com> | 2021-09-19 13:09:13 +0200 |
|---|---|---|
| committer |   Gustavo A. R. Silva <gustavoars@kernel.org> | 2021-10-13 14:54:13 -0500 |
| commit | 2a12e0003580505b8e7d82f9a8fef95f4a1031a8 (patch) | |
| tree | 12de26f4ed82cf4306af29a4948ebc91aabcf62b /lib/assoc_array.c | |
| parent | Linux 5.15-rc2 (diff) | |
| download | linux-dev-2a12e0003580505b8e7d82f9a8fef95f4a1031a8.tar.xz linux-dev-2a12e0003580505b8e7d82f9a8fef95f4a1031a8.zip | |
assoc_array: Avoid open coded arithmetic in allocator arguments
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 struct_size() helper to do the arithmetic instead of the
argument "size + count * size" in the kmalloc() and kzalloc() functions.
Also, take the opportunity to refactor the memcpy() calls to use the
struct_size() and flex_array_size() helpers.
[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments
Signed-off-by: Len Baker <len.baker@gmx.com>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Diffstat (limited to 'lib/assoc_array.c')
| -rw-r--r-- | lib/assoc_array.c | 22 |
1 files changed, 10 insertions, 12 deletions
diff --git a/lib/assoc_array.c b/lib/assoc_array.c index 04c98799c3ba..079c72e26493 100644 --- a/lib/assoc_array.c +++ b/lib/assoc_array.c @@ -741,8 +741,7 @@ all_leaves_cluster_together: keylen = round_up(diff, ASSOC_ARRAY_KEY_CHUNK_SIZE); keylen >>= ASSOC_ARRAY_KEY_CHUNK_SHIFT; - new_s0 = kzalloc(sizeof(struct assoc_array_shortcut) + - keylen * sizeof(unsigned long), GFP_KERNEL); + new_s0 = kzalloc(struct_size(new_s0, index_key, keylen), GFP_KERNEL); if (!new_s0) return false; edit->new_meta[2] = assoc_array_shortcut_to_ptr(new_s0); @@ -849,8 +848,8 @@ static bool assoc_array_insert_mid_shortcut(struct assoc_array_edit *edit, keylen = round_up(diff, ASSOC_ARRAY_KEY_CHUNK_SIZE); keylen >>= ASSOC_ARRAY_KEY_CHUNK_SHIFT; - new_s0 = kzalloc(sizeof(struct assoc_array_shortcut) + - keylen * sizeof(unsigned long), GFP_KERNEL); + new_s0 = kzalloc(struct_size(new_s0, index_key, keylen), + GFP_KERNEL); if (!new_s0) return false; edit->new_meta[1] = assoc_array_shortcut_to_ptr(new_s0); @@ -864,7 +863,7 @@ static bool assoc_array_insert_mid_shortcut(struct assoc_array_edit *edit, new_n0->parent_slot = 0; memcpy(new_s0->index_key, shortcut->index_key, - keylen * sizeof(unsigned long)); + flex_array_size(new_s0, index_key, keylen)); blank = ULONG_MAX << (diff & ASSOC_ARRAY_KEY_CHUNK_MASK); pr_devel("blank off [%zu] %d: %lx\n", keylen - 1, diff, blank); @@ -899,8 +898,8 @@ static bool assoc_array_insert_mid_shortcut(struct assoc_array_edit *edit, keylen = round_up(shortcut->skip_to_level, ASSOC_ARRAY_KEY_CHUNK_SIZE); keylen >>= ASSOC_ARRAY_KEY_CHUNK_SHIFT; - new_s1 = kzalloc(sizeof(struct assoc_array_shortcut) + - keylen * sizeof(unsigned long), GFP_KERNEL); + new_s1 = kzalloc(struct_size(new_s1, index_key, keylen), + GFP_KERNEL); if (!new_s1) return false; edit->new_meta[2] = assoc_array_shortcut_to_ptr(new_s1); @@ -913,7 +912,7 @@ static bool assoc_array_insert_mid_shortcut(struct assoc_array_edit *edit, new_n0->slots[sc_slot] = assoc_array_shortcut_to_ptr(new_s1); memcpy(new_s1->index_key, shortcut->index_key, - keylen * sizeof(unsigned long)); + flex_array_size(new_s1, index_key, keylen)); edit->set[1].ptr = &side->back_pointer; edit->set[1].to = assoc_array_shortcut_to_ptr(new_s1); @@ -1490,13 +1489,12 @@ descend: shortcut = assoc_array_ptr_to_shortcut(cursor); keylen = round_up(shortcut->skip_to_level, ASSOC_ARRAY_KEY_CHUNK_SIZE); keylen >>= ASSOC_ARRAY_KEY_CHUNK_SHIFT; - new_s = kmalloc(sizeof(struct assoc_array_shortcut) + - keylen * sizeof(unsigned long), GFP_KERNEL); + new_s = kmalloc(struct_size(new_s, index_key, keylen), + GFP_KERNEL); if (!new_s) goto enomem; pr_devel("dup shortcut %p -> %p\n", shortcut, new_s); - memcpy(new_s, shortcut, (sizeof(struct assoc_array_shortcut) + - keylen * sizeof(unsigned long))); + memcpy(new_s, shortcut, struct_size(new_s, index_key, keylen)); new_s->back_pointer = new_parent; new_s->parent_slot = shortcut->parent_slot; *new_ptr_pp = new_parent = assoc_array_shortcut_to_ptr(new_s); |