In the Linux kernel, the following vulnerability has been resolved:
binder: fix async_free_space accounting for empty parcels
In 4.13, commit 74310e06be4d (“android: binder: Move buffer out of area shared with user space”)
fixed a kernel structure visibility issue. As part of that patch,
sizeof(void *) was used as the buffer size for 0-length data payloads so
the driver could detect abusive clients sending 0-length asynchronous
transactions to a server by enforcing limits on async_free_size.
Unfortunately, on the “free” side, the accounting of async_free_space
did not add the sizeof(void *) back. The result was that up to 8-bytes of
async_free_space were leaked on every async transaction of 8-bytes or
less. These small transactions are uncommon, so this accounting issue
has gone undetected for several years.
The fix is to use “buffer_size” (the allocated buffer size) instead of
“size” (the logical buffer size) when updating the async_free_space
during the free operation. These are the same except for this
corner case of asynchronous transactions with payloads < 8 bytes.
[
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "unaffected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"drivers/android/binder_alloc.c"
],
"versions": [
{
"version": "74310e06be4d",
"lessThan": "2d2df539d052",
"status": "affected",
"versionType": "git"
},
{
"version": "74310e06be4d",
"lessThan": "7c7064402609",
"status": "affected",
"versionType": "git"
},
{
"version": "74310e06be4d",
"lessThan": "103b16a8c51f",
"status": "affected",
"versionType": "git"
},
{
"version": "74310e06be4d",
"lessThan": "1cb8444f3114",
"status": "affected",
"versionType": "git"
},
{
"version": "74310e06be4d",
"lessThan": "17691bada6b2",
"status": "affected",
"versionType": "git"
},
{
"version": "74310e06be4d",
"lessThan": "cfd0d84ba28c",
"status": "affected",
"versionType": "git"
}
]
},
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "affected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"drivers/android/binder_alloc.c"
],
"versions": [
{
"version": "4.14",
"status": "affected"
},
{
"version": "0",
"lessThan": "4.14",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "4.14.261",
"lessThanOrEqual": "4.14.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "4.19.224",
"lessThanOrEqual": "4.19.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.4.170",
"lessThanOrEqual": "5.4.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.10.90",
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.15.13",
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.16",
"lessThanOrEqual": "*",
"status": "unaffected",
"versionType": "original_commit_for_fix"
}
]
}
]
git.kernel.org/stable/c/103b16a8c51f96d5fe063022869ea906c256e5da
git.kernel.org/stable/c/17691bada6b2f1d5f1c0f6d28cd9d0727023b0ff
git.kernel.org/stable/c/1cb8444f3114f0bb2f6e3bcadcf09aa4a28425d4
git.kernel.org/stable/c/2d2df539d05205fd83c404d5f2dff48d36f9b495
git.kernel.org/stable/c/7c7064402609aeb6fb11be1b4ec10673ff17b593
git.kernel.org/stable/c/cfd0d84ba28c18b531648c9d4a35ecca89ad9901