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| author | Liam R. Howlett <[email protected]> | 2024-04-22 20:33:49 +0000 |
|---|---|---|
| committer | Andrew Morton <[email protected]> | 2024-05-06 00:28:05 +0000 |
| commit | 955a923d2809803980ff574270f81510112be9cf (patch) | |
| tree | 4f6026e03233204fd3bbc50d6d3abfb406a7d69b /lib/test_xarray.c | |
| parent | mm/userfaultfd: reset ptes when close() for wr-protected ones (diff) | |
| download | kernel-955a923d2809803980ff574270f81510112be9cf.tar.gz kernel-955a923d2809803980ff574270f81510112be9cf.zip | |
maple_tree: fix mas_empty_area_rev() null pointer dereference
Currently the code calls mas_start() followed by mas_data_end() if the
maple state is MA_START, but mas_start() may return with the maple state
node == NULL. This will lead to a null pointer dereference when checking
information in the NULL node, which is done in mas_data_end().
Avoid setting the offset if there is no node by waiting until after the
maple state is checked for an empty or single entry state.
A user could trigger the events to cause a kernel oops by unmapping all
vmas to produce an empty maple tree, then mapping a vma that would cause
the scenario described above.
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Liam R. Howlett <[email protected]>
Reported-by: Marius Fleischer <[email protected]>
Closes: https://lore.kernel.org/lkml/CAJg=8jyuSxDL6XvqEXY_66M20psRK2J53oBTP+fjV5xpW2-R6w@mail.gmail.com/
Link: https://lore.kernel.org/lkml/CAJg=8jyuSxDL6XvqEXY_66M20psRK2J53oBTP+fjV5xpW2-R6w@mail.gmail.com/
Tested-by: Marius Fleischer <[email protected]>
Tested-by: Sidhartha Kumar <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Diffstat (limited to 'lib/test_xarray.c')
0 files changed, 0 insertions, 0 deletions