Description
In the Linux kernel, the following vulnerability has been resolved: drbd: fix "LOGIC BUG" in drbd_al_begin_io_nonblock() Even though we check that we "should" be able to do lc_get_cumulative() while holding the device->al_lock spinlock, it may still fail, if some other code path decided to do lc_try_lock() with bad timing. If that happened, we logged "LOGIC BUG for enr=...", but still did not return an error. The rest of the code now assumed that this request has references for the relevant activity log extents. The implcations are that during an active resync, mutual exclusivity of resync versus application IO is not guaranteed. And a potential crash at this point may not realizs that these extents could have been target of in-flight IO and would need to be resynced just in case. Also, once the request completes, it will give up activity log references it does not even hold, which will trigger a BUG_ON(refcnt == 0) in lc_put(). Fix: Do not crash the kernel for a condition that is harmless during normal operation: also catch "e->refcnt == 0", not only "e == NULL" when being noisy about "al_complete_io() called on inactive extent %u\n". And do not try to be smart and "guess" whether something will work, then be surprised when it does not. Deal with the fact that it may or may not work. If it does not, remember a possible "partially in activity log" state (only possible for requests that cross extent boundaries), and return an error code from drbd_al_begin_io_nonblock(). A latter call for the same request will then resume from where we left off.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
08a1ddab6df7d3c7b6341774cb1cf4b21b96a214 to < 933d161baa3794547adee621c0bf52cbf2c1b3cdaffected08a1ddab6df7d3c7b6341774cb1cf4b21b96a214 to < cf01aa6288e1190f89865e765056e2a9d8190639affected08a1ddab6df7d3c7b6341774cb1cf4b21b96a214 to < 7752569fc78e89794ce28946529850282233f99daffected08a1ddab6df7d3c7b6341774cb1cf4b21b96a214 to < e91d8d6565b7819d13dab21d4dbed5b45efba59baffected08a1ddab6df7d3c7b6341774cb1cf4b21b96a214 to < eef1390125b660b8b61f9f227a03bb9c5e6d36a5affected08a1ddab6df7d3c7b6341774cb1cf4b21b96a214 to < d1ef3aed4df2ef1fe46befd8f2da9a6ec5445508affected08a1ddab6df7d3c7b6341774cb1cf4b21b96a214 to < f558e5404a72054b525dced1a0c66aa95a144153affected08a1ddab6df7d3c7b6341774cb1cf4b21b96a214 to < ab140365fb62c0bdab22b2f516aff563b2559e3baffected
Linux Linux
Default version status: affected
3.10affected0 to < 3.10unaffected5.10.253 to ≤ 5.10.*unaffected5.15.203 to ≤ 5.15.*unaffected6.1.167 to ≤ 6.1.*unaffected6.6.130 to ≤ 6.6.*unaffected6.12.77 to ≤ 6.12.*unaffected6.18.17 to ≤ 6.18.*unaffected6.19.7 to ≤ 6.19.*unaffected7.0 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/933d161baa3794547adee621c0bf52cbf2c1b3cd ↗
- https://git.kernel.org/stable/c/cf01aa6288e1190f89865e765056e2a9d8190639 ↗
- https://git.kernel.org/stable/c/7752569fc78e89794ce28946529850282233f99d ↗
- https://git.kernel.org/stable/c/e91d8d6565b7819d13dab21d4dbed5b45efba59b ↗
- https://git.kernel.org/stable/c/eef1390125b660b8b61f9f227a03bb9c5e6d36a5 ↗
- https://git.kernel.org/stable/c/d1ef3aed4df2ef1fe46befd8f2da9a6ec5445508 ↗
- https://git.kernel.org/stable/c/f558e5404a72054b525dced1a0c66aa95a144153 ↗
- https://git.kernel.org/stable/c/ab140365fb62c0bdab22b2f516aff563b2559e3b ↗
- https://cert-portal.siemens.com/productcert/html/ssa-784472.html ↗