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| author |   Carlos Maiolino <cmaiolino@redhat.com> | 2020-01-09 14:30:45 +0100 |
|---|---|---|
| committer |   Al Viro <viro@zeniv.linux.org.uk> | 2020-02-03 08:05:58 -0500 |
| commit | 324282c0252a44a97d628813e30ea7258940d469 (patch) | |
| tree | a22618816695a6fa7e078319ba003be102bba12f /mm | |
| parent | fibmap: Use bmap instead of ->bmap method in ioctl_fibmap (diff) | |
| download | linux-dev-324282c0252a44a97d628813e30ea7258940d469.tar.xz linux-dev-324282c0252a44a97d628813e30ea7258940d469.zip | |
fibmap: Reject negative block numbers
FIBMAP receives an integer from userspace which is then implicitly converted
into sector_t to be passed to bmap(). No check is made to ensure userspace
didn't send a negative block number, which can end up in an underflow, and
returning to userspace a corrupted block address.
As a side-effect, the underflow caused by a negative block here, will
trigger the WARN() in iomap_bmap_actor(), which is how this issue was
first discovered.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'mm')
0 files changed, 0 insertions, 0 deletions