CVE-2026-89953
Description
In the Linux kernel, the following vulnerability has been resolved: mtd: mtdoops: free page bitmap when the backing MTD is removed mtdoops_notify_add() allocates oops_page_used when the configured MTD device is registered. mtdoops_notify_remove() detaches from that device but leaves the bitmap allocated. If the same MTD device is later registered again, the add path allocates a new bitmap and overwrites the old pointer, leaking one vmalloc allocation per remove/add cycle. This is only visible when the backing MTD device can disappear and be registered again while mtdoops remains loaded, so the usual static MTD case does not expose it. Free the bitmap after unregistering the dumper and flushing the pending workers, then clear the pointer and page count before a later attach can allocate fresh state. Clearing the pointer also keeps the module exit path from freeing the same bitmap a second time after a remove event.
How to fix
- Linux Linux477d61d54e097e90f748aa18d013805abd56bcbd, a91ac71e67c3e01ed9afd9841435bebb930293f8, 698944132083d143ef965c0090ee14ba1d9e1a5f, f25c804947e0a28c15e73da8e2e0db959cbed716, 8414f0e9f707226de20b48c7048179fd86d352fc, d06f91a52af11630c9f7e487f6daf242ac310cb8, 1e5cd8bc902331ff801df88cbb299029ae062753, 956e7da12c114f13c63d126ab1d79c3b6a819060 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| Linux Linux | be95745f01677245a061a8f51473ef5ec8ad008e ≤ v < 477d61d54e097e90f748aa18d013805abd56bcbd, be95745f01677245a061a8f51473ef5ec8ad008e ≤ v < a91ac71e67c3e01ed9afd9841435bebb930293f8, be95745f01677245a061a8f51473ef5ec8ad008e ≤ v < 698944132083d143ef965c0090ee14ba1d9e1a5f, be95745f01677245a061a8f51473ef5ec8ad008e ≤ v < f25c804947e0a28c15e73da8e2e0db959cbed716, be95745f01677245a061a8f51473ef5ec8ad008e ≤ v < 8414f0e9f707226de20b48c7048179fd86d352fc, be95745f01677245a061a8f51473ef5ec8ad008e ≤ v < d06f91a52af11630c9f7e487f6daf242ac310cb8, be95745f01677245a061a8f51473ef5ec8ad008e ≤ v < 1e5cd8bc902331ff801df88cbb299029ae062753, be95745f01677245a061a8f51473ef5ec8ad008e ≤ v < 956e7da12c114f13c63d126ab1d79c3b6a819060, 2.6.33 | 477d61d54e097e90f748aa18d013805abd56bcbd, a91ac71e67c3e01ed9afd9841435bebb930293f8, 698944132083d143ef965c0090ee14ba1d9e1a5f, f25c804947e0a28c15e73da8e2e0db959cbed716, 8414f0e9f707226de20b48c7048179fd86d352fc, d06f91a52af11630c9f7e487f6daf242ac310cb8, 1e5cd8bc902331ff801df88cbb299029ae062753, 956e7da12c114f13c63d126ab1d79c3b6a819060 |
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