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| author | Herbert Xu <herbert@gondor.apana.org.au> | 2023-12-02 09:01:54 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-01-31 16:18:50 -0800 |
| commit | ecabe8cd456d3bf81e92c53b074732f3140f170d (patch) | |
| tree | 3c07bcc34cc39f60910d64c1961d05e70f4cd457 /arch/s390 | |
| parent | 7692e29d191c097e406126413769bdde8f2670b7 (diff) | |
| download | linux-stable-ecabe8cd456d3bf81e92c53b074732f3140f170d.tar.gz linux-stable-ecabe8cd456d3bf81e92c53b074732f3140f170d.tar.bz2 linux-stable-ecabe8cd456d3bf81e92c53b074732f3140f170d.zip | |
hwrng: core - Fix page fault dead lock on mmap-ed hwrng
commit 78aafb3884f6bc6636efcc1760c891c8500b9922 upstream.
There is a dead-lock in the hwrng device read path. This triggers
when the user reads from /dev/hwrng into memory also mmap-ed from
/dev/hwrng. The resulting page fault triggers a recursive read
which then dead-locks.
Fix this by using a stack buffer when calling copy_to_user.
Reported-by: Edward Adam Davis <eadavis@qq.com>
Reported-by: syzbot+c52ab18308964d248092@syzkaller.appspotmail.com
Fixes: 9996508b3353 ("hwrng: core - Replace u32 in driver API with byte array")
Cc: <stable@vger.kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/s390')
0 files changed, 0 insertions, 0 deletions