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| author | Sergey Shtylyov <s.shtylyov@omp.ru> | 2024-03-27 19:52:49 +0300 |
|---|---|---|
| committer | Rob Herring <robh@kernel.org> | 2024-03-28 01:05:07 +0300 |
| commit | a1aa5390cc912934fee76ce80af5f940452fa987 (patch) | |
| tree | 6b7c0b89a30267467d890822958087927706b989 /drivers/of | |
| parent | b5237d0bdb3cb164b7792cc4f1ff2ecafbfac661 (diff) | |
| download | linux-a1aa5390cc912934fee76ce80af5f940452fa987.tar.xz | |
of: module: prevent NULL pointer dereference in vsnprintf()
In of_modalias(), we can get passed the str and len parameters which would
cause a kernel oops in vsnprintf() since it only allows passing a NULL ptr
when the length is also 0. Also, we need to filter out the negative values
of the len parameter as these will result in a really huge buffer since
snprintf() takes size_t parameter while ours is ssize_t...
Found by Linux Verification Center (linuxtesting.org) with the Svace static
analysis tool.
Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/1d211023-3923-685b-20f0-f3f90ea56e1f@omp.ru
Signed-off-by: Rob Herring <robh@kernel.org>
Diffstat (limited to 'drivers/of')
| -rw-r--r-- | drivers/of/module.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/of/module.c b/drivers/of/module.c index 0e8aa974f0f2..f58e624953a2 100644 --- a/drivers/of/module.c +++ b/drivers/of/module.c @@ -16,6 +16,14 @@ ssize_t of_modalias(const struct device_node *np, char *str, ssize_t len) ssize_t csize; ssize_t tsize; + /* + * Prevent a kernel oops in vsnprintf() -- it only allows passing a + * NULL ptr when the length is also 0. Also filter out the negative + * lengths... + */ + if ((len > 0 && !str) || len < 0) + return -EINVAL; + /* Name & Type */ /* %p eats all alphanum characters, so %c must be used here */ csize = snprintf(str, len, "of:N%pOFn%c%s", np, 'T', |