Answer in brief
CVE-2025-21855 records a Unknown severity vulnerability in ibmvnic: Don't reference skb after sending to VIOS. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=032c5e82847a2214c3196a90f0aeba0ce252de58 <501ac6a7e21b82e05207c6b4449812d82820f306 || >=032c5e82847a2214c3196a90f0aeba0ce252de58 <093b0e5c90592773863f300b908b741622eef597 || >=032c5e82847a2214c3196a90f0aeba0ce252de58 <25dddd01dcc8ef3acff964dbb32eeb0d89f098e9 || >=032c5e82847a2214c3196a90f0aeba0ce252de58 <abaff2717470e4b5b7c0c3a90e128b211a23da09 || >=032c5e82847a2214c3196a90f0aeba0ce252de58 <bdf5d13aa05ec314d4385b31ac974d6c7e0997c9 | 501ac6a7e21b82e05207c6b4449812d82820f306, 093b0e5c90592773863f300b908b741622eef597, 25dddd01dcc8ef3acff964dbb32eeb0d89f098e9, abaff2717470e4b5b7c0c3a90e128b211a23da09, bdf5d13aa05ec314d4385b31ac974d6c7e0997c9 |
| Linux/Linuxgeneric | 4.5 | Not reported |
Published upstream
Mar 12, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: ibmvnic: Don't reference skb after sending to VIOS Previously, after successfully flushing the xmit buffer to VIOS, the tx_bytes stat was incremented by the length of the skb. It is invalid to access the skb memory after sending the buffer to the VIOS because, at any point after sending, the VIOS can trigger an interrupt to free this memory. A race between reading skb->len and freeing the skb is possible (especially during LPM) and will result in use-after-free: ================================================================== BUG: KASAN: slab-use-after-free in ibmvnic_xmit+0x75c/0x1808 [ibmvnic] Read of size 4 at addr c00000024eb48a70 by task hxecom/14495 <...> Call Trace: [c000000118f66cf0] [c0000000018cba6c] dump_stack_lvl+0x84/0xe8 (unreliable) [c000000118f66d20] [c0000000006f0080] print_report+0x1a8/0x7f0 [c000000118f66df0] [c0000000006f08f0] kasan_report+0x128/0x1f8 [c000000118f66f00] [c0000000006f2868] __asan_load4+0xac/0xe0 [c000000118f66f20] [c0080000046eac84] ibmvnic_xmit+0x75c/0x1808 [ibmvnic] [c000000118f67340] [c0000000014be168] dev_hard_start_xmit+0x150/0x358 <...> Freed by task 0: kasan_save_stack+0x34/0x68 kasan_save_track+0x2c/0x50 kasan_save_free_info+0x64/0x108 __kasan_mempool_poison_object+0x148/0x2d4 napi_skb_cache_put+0x5c/0x194 net_tx_action+0x154/0x5b8 handle_softirqs+0x20c/0x60c do_softirq_own_stack+0x6c/0x88 <...> The buggy address belongs to the object at c00000024eb48a00 which belongs to the cache skbuff_head_cache of size 224 ==================================================================
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2025-21855 records a Unknown severity vulnerability in ibmvnic: Don't reference skb after sending to VIOS. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=032c5e82847a2214c3196a90f0aeba0ce252de58 <501ac6a7e21b82e05207c6b4449812d82820f306 || >=032c5e82847a2214c3196a90f0aeba0ce252de58 <093b0e5c90592773863f300b908b741622eef597 || >=032c5e82847a2214c3196a90f0aeba0ce252de58 <25dddd01dcc8ef3acff964dbb32eeb0d89f098e9 || >=032c5e82847a2214c3196a90f0aeba0ce252de58 <abaff2717470e4b5b7c0c3a90e128b211a23da09 || >=032c5e82847a2214c3196a90f0aeba0ce252de58 <bdf5d13aa05ec314d4385b31ac974d6c7e0997c9 | 501ac6a7e21b82e05207c6b4449812d82820f306, 093b0e5c90592773863f300b908b741622eef597, 25dddd01dcc8ef3acff964dbb32eeb0d89f098e9, abaff2717470e4b5b7c0c3a90e128b211a23da09, bdf5d13aa05ec314d4385b31ac974d6c7e0997c9 |
| Linux/Linuxgeneric | 4.5 | Not reported |
Published upstream
Mar 12, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: ibmvnic: Don't reference skb after sending to VIOS Previously, after successfully flushing the xmit buffer to VIOS, the tx_bytes stat was incremented by the length of the skb. It is invalid to access the skb memory after sending the buffer to the VIOS because, at any point after sending, the VIOS can trigger an interrupt to free this memory. A race between reading skb->len and freeing the skb is possible (especially during LPM) and will result in use-after-free: ================================================================== BUG: KASAN: slab-use-after-free in ibmvnic_xmit+0x75c/0x1808 [ibmvnic] Read of size 4 at addr c00000024eb48a70 by task hxecom/14495 <...> Call Trace: [c000000118f66cf0] [c0000000018cba6c] dump_stack_lvl+0x84/0xe8 (unreliable) [c000000118f66d20] [c0000000006f0080] print_report+0x1a8/0x7f0 [c000000118f66df0] [c0000000006f08f0] kasan_report+0x128/0x1f8 [c000000118f66f00] [c0000000006f2868] __asan_load4+0xac/0xe0 [c000000118f66f20] [c0080000046eac84] ibmvnic_xmit+0x75c/0x1808 [ibmvnic] [c000000118f67340] [c0000000014be168] dev_hard_start_xmit+0x150/0x358 <...> Freed by task 0: kasan_save_stack+0x34/0x68 kasan_save_track+0x2c/0x50 kasan_save_free_info+0x64/0x108 __kasan_mempool_poison_object+0x148/0x2d4 napi_skb_cache_put+0x5c/0x194 net_tx_action+0x154/0x5b8 handle_softirqs+0x20c/0x60c do_softirq_own_stack+0x6c/0x88 <...> The buggy address belongs to the object at c00000024eb48a00 which belongs to the cache skbuff_head_cache of size 224 ==================================================================
Quoted source text, attributed separately from HOL analysis.