Bug 2395347 (CVE-2022-50293) - CVE-2022-50293 kernel: btrfs: do not BUG_ON() on ENOMEM when dropping extent items for a range
Summary: CVE-2022-50293 kernel: btrfs: do not BUG_ON() on ENOMEM when dropping extent ...
Keywords:
Status: NEW
Alias: CVE-2022-50293
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2025-09-15 15:08 UTC by OSIDB Bzimport
Modified: 2025-09-15 20:47 UTC (History)
0 users

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Description OSIDB Bzimport 2025-09-15 15:08:51 UTC
In the Linux kernel, the following vulnerability has been resolved:

btrfs: do not BUG_ON() on ENOMEM when dropping extent items for a range

If we get -ENOMEM while dropping file extent items in a given range, at
btrfs_drop_extents(), due to failure to allocate memory when attempting to
increment the reference count for an extent or drop the reference count,
we handle it with a BUG_ON(). This is excessive, instead we can simply
abort the transaction and return the error to the caller. In fact most
callers of btrfs_drop_extents(), directly or indirectly, already abort
the transaction if btrfs_drop_extents() returns any error.

Also, we already have error paths at btrfs_drop_extents() that may return
-ENOMEM and in those cases we abort the transaction, like for example
anything that changes the b+tree may return -ENOMEM due to a failure to
allocate a new extent buffer when COWing an existing extent buffer, such
as a call to btrfs_duplicate_item() for example.

So replace the BUG_ON() calls with proper logic to abort the transaction
and return the error.


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