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| author | Eric Dumazet <[email protected]> | 2025-06-11 11:15:12 +0000 |
|---|---|---|
| committer | Jakub Kicinski <[email protected]> | 2025-06-12 15:05:49 +0000 |
| commit | 85a3e0ede38450ea3053b8c45d28cf55208409b8 (patch) | |
| tree | 888a3280cf551a7d946eedd5bcb547b191e68cee /drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | |
| parent | net_sched: prio: fix a race in prio_tune() (diff) | |
| download | kernel-85a3e0ede38450ea3053b8c45d28cf55208409b8.tar.gz kernel-85a3e0ede38450ea3053b8c45d28cf55208409b8.zip | |
net_sched: red: fix a race in __red_change()
Gerrard Tai reported a race condition in RED, whenever SFQ perturb timer
fires at the wrong time.
The race is as follows:
CPU 0 CPU 1
[1]: lock root
[2]: qdisc_tree_flush_backlog()
[3]: unlock root
|
| [5]: lock root
| [6]: rehash
| [7]: qdisc_tree_reduce_backlog()
|
[4]: qdisc_put()
This can be abused to underflow a parent's qlen.
Calling qdisc_purge_queue() instead of qdisc_tree_flush_backlog()
should fix the race, because all packets will be purged from the qdisc
before releasing the lock.
Fixes: 0c8d13ac9607 ("net: sched: red: delay destroying child qdisc on replace")
Reported-by: Gerrard Tai <[email protected]>
Suggested-by: Gerrard Tai <[email protected]>
Signed-off-by: Eric Dumazet <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
Diffstat (limited to 'drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c')
0 files changed, 0 insertions, 0 deletions